Anonymous (1975). Study of the Auditory Perception of Dolphin As a Function of Signal Characteristics in the Time Domain, Joint Publications Research Service: Arlington, Va, 7 p.
NAL Call Number: TRANSL 24709
Descriptors: dolphins, auditory perception, signal characteristics, study.
Notes: Translated from Russian, JPRS 65877.
Acevedo Gutierrez, A. and S.C. Stienessen (2004). Bottlenose dolphins (Tursiops truncatus) increase number of whistles when feeding. Aquatic Mammals 30(3): 357-362. ISSN: 0167-5427.
Descriptors: Tursiops truncatus, echolocation, sound production rate, relationships, feeding behavior, cooperative behavior, North Pacific, Costa Rica, Isla del Coco, recruitment to feeding events, sound production rate relationships.
Akamatsu, T. (1997). Developments of echolocation event detectors and their application for small cetaceans (Phocoena phocoena and Tursiops truncatus). Bulletin of National Research Institute of Fisheries Engineering (18): 155-206. ISSN: 0388-9718.
Descriptors: Phocoena, sound, monitoring, measuring instruments, Tursiops, sensors, fish detection, behavior, Cetacea, dolphins, equipment, fishing operations, mammals, measuring instruments, radiation.
Language of Text: English summary.
Akamatsu, T., Y. Hatakeyama, K. Ishii, H. Soeda, T. Shimamura, and T. Kojima (1994). A telemetry system for counting the number of echolocation and an experiment regarding a harbor porpoises (Phocoena phocoena). Bulletin of National Research Institute of Fisheries Engineering (15): 145-156. ISSN: 0388-9718.
NAL Call Number: SH301.S852
Abstract: The echolocation ability of trained dolphins have been studied for a long time, They say that dolphins can recognize a netting of a gill net from the distance between 2 to 14 m due to echolocation, but many dolphins and porpoises have been caught in gill nets accidentally. Up until now, few studies have been made on the echolocation rate. We developed a telemetry device to count the number of echolocation. The echolocation signal (clicks) above 150 dBrel mu Pa with a peak energy frequency between 50 to 130 kHz are counted. This detection circuit has been called click light since it lights up at detection. This circuit can be used as a simple telemetry system for counting the number of echolocation. The telemetry system consists of a click light circuit, four bit data counter and transmission circuit. The data counter can be reset when a dolphin surfaces. Pulse code modulated signals from the transmitter can be received at a distance of 5 km. The transmitter device can be attached to dolphins or porpoises. The experiment with the click light and telemetry system was conducted in a circular pool (6m in diameter and 1m in depth) and a net enclosure (20m x 10m area and about 6m deep). In this experiment, harbor porpoises were used. The echolocation rate was changed frequently ranging from 0 to 20 times/min. The food, illumination, width of enclosure and configuration of the netting seemed to have some influence on the echolocation rate. Human activity such as approaching the pool caused the echolocation rate to increase. It is thought that any novel acoustic or visual stimuli increase the rate of echolocation. If a dolphin swims at 5m/s and the recognition range of the gill net is 10m, it must echolocate once in 2 sec to avoid being caught accidentally. Therefore, the rates of the stimulation must be larger than this rate.
Descriptors: Phocoena, ultrasonics, echosounding, location factors, telemetry, acoustic properties, equipment, experimentation, chemicophysical properties, measurement, production location, radiations, sound.
Language of Text: English summary.
Akamatsu, T., Y. Hatakeyama, and N. Takatsu (1993). Effects of pulse sounds on escape behavior of false killer whales. Bulletin of the Japanese Society of Scientific Fisheries 59(8): 1297-1303. ISSN: 0021-5392.
Descriptors: dolphins, noise, behavior, accident prevention, equipment, sound, Cetacea, mammals, pollutants, radiations, safety.
Language of Text: English and Japanese summaries.
Akamatsu, T., D. Wang, K. Wang, and Y. Naito (2005). Biosonar behaviour of free-ranging porpoises. Proceedings of the Royal Society of London. Series B. Biological Sciences 272(1565): 797-801. ISSN: 0962-8452.
Abstract: Detecting objects in their paths is a fundamental perceptional function of moving organisms. Potential risks and rewards, such as prey, predators, conspecifics or non-biological obstacles, must be detected so that an animal can modify its behaviour accordingly. However, to date few studies have considered how animals in the wild focus their attention. Dolphins and porpoises are known to actively use sonar or echolocation. A newly developed miniature data logger attached to a porpoise allows for individual recording of acoustical search efforts and inspection distance based on echolocation. In this study, we analysed the biosonar behaviour of eight free-ranging finless porpoises (Neophocaena phocaenoides) and demonstrated that these animals inspect the area ahead of them before swimming silently into it. The porpoises inspected distances up to 77 m, whereas their swimming distance without using sonar was less than 20 m. The inspection distance was long enough to ensure a wide safety margin before facing real risks or rewards. Once a potential prey item was detected, porpoises adjusted their inspection distance from the remote target throughout their approach.
Descriptors: porpoises, free ranging, biosonar, objects, detecting, prey, acoustical, echolocation.
Akamatsu, T., D. Wang, K. Wang, and Z. Wei (2001). Comparison between visual and passive acoustic detection of finless porpoises in the Yangtze River, China. Journal of the Acoustical Society of America 109(4): 1723-7. ISSN: 0001-4966.
Abstract: Recently, sonar signals and other sounds produced by cetaceans have been used for acoustic detection of individuals and groups in the wild. However, the detection probability ascertained by concomitant visual survey has not been demonstrated extensively. The finless porpoises (Neophocaena phocaenoides) have narrow band and high-frequency sonar signals, which are distinctive from background noises. Underwater sound monitoring with hydrophones (B&K8103) placed along the sides of a research vessel, concurrent with visual observations was conducted in the Yangtze River from Wuhan to Poyang Lake in 1998 in China. The peak to peak detection threshold was set at 133 dB re 1,EPa. With this threshold level, porpoises could be detected reliably within 300 m of the hydrophone. In a total of 774-km cruise, 588 finless porpoises were sighted by visual observation and 44,864 ultrasonic pulses were recorded by the acoustical observation system. The acoustic monitoring system could detect the presence of the finless porpoises 82% of the time. A false alarm in the system occurred with a frequency of 0.9%. The high-frequency acoustical observation is suggested as an effective method for field surveys of small cetaceans, which produce high-frequency sonar signals.
Descriptors: auditory perception physiology, echolocation physiology, porpoises physiology, visual perception physiology, China, time factors.
Akamatsu, T., Y. Hatakeyama, T. Kojima, and H. Soeda (1994). Echolocation rates of two harbor porpoises (Phocoena phocoena). Marine Mammal Science 10(4): 401-411. ISSN: 0824-0469.
NAL Call Number: QL713.2.M372
Abstract: The rate of occurrence of click trains of two harbor porpoises (Phocoena phocoena) were counted during 14 nights. We developed an echolocation signal detection system that was harnessed to a porpoise and activated a light when the animal emitted an echolocation signal. This device, referred to as a click-light, detects echolocation signals above 150 dB re 1 mu-Pa in the 28-180 kHz range. Echolocation rates, i.e., occurrences of click trains, changed frequently, ranging from 0 to 25 per minute. Echolocation rates were affected by feeding, individual difference, and enclosure type such as the net enclosure and the pool. The porpoise echolocation rates seemed to snow acclimation.
Descriptors: behavior, communication, ecology, environmental sciences, marine ecology, ecology, environmental sciences, nutrition, behavior, feeding.
Altesa, R.A., L.A. Dankiewicz, P.W. Moore, and D.A. Helweg (2003). Multiecho processing by an echolocating dolphin. Journal of the Acoustical Society of America 114(2): 1155-66. ISSN: 0001-4966.
Abstract: Bottlenose dolphins (Tursiops truncatus) use short, wideband pulses for echolocation. Individual waveforms have high-range resolution capability but are relatively insensitive to range rate. Signal-to-noise ratio (SNR) is not greatly improved by pulse compression because each waveform has small time-bandwidth product. The dolphin, however, often uses many pulses to interrogate a target, and could use multipulse processing to combine the resulting echoes. Multipulse processing could mitigate the small SNR improvement from pulse compression, and could greatly improve range-rate estimation, moving target indication, range tracking, and acoustic imaging. All these hypothetical capabilities depend upon the animal's ability to combine multiple echoes for detection and/or estimation. An experiment to test multiecho processing in a dolphin measured detection of a stationary target when the number N of available target echoes was increased, using synthetic echoes. The SNR required for detection decreased as the number of available echoes increased, as expected for multiecho processing. A receiver that sums binary-quantized data samples from multiple echoes closely models the N dependence of the SNR required by the dolphin. Such a receiver has distribution-tolerant (nonparametric) properties that make it robust in environments with nonstationary and/or non-Gaussian noise, such as the pulses created by snapping shrimp.
Descriptors: echolocation, acoustics, auditory threshold, behavior, animal, dolphins, ultrasonics, vocalization, animal.
Amundin, M. and S.H. Andersen (1983). Bony nares air pressure and nasal plug muscle activity during click produciton in the harbour porpoise, Phocoena phocoena, and the bottlenosed dolphin, Tursiops truncatus. Journal of Experimental Biology 105: 275-282. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Descriptors: porpoise, dolphin, click production, bony nares, air pressure, nasal plug, muscle activity, Phocoena, Tursiops.
Andre, M., A. Supin, E. Delory, C. Kamminga, E. Degollada, and J.M. Alonso (2003). Evidence of deafness in a striped dolphin, Stenella coeruleoalba. Aquatic Mammals 29(1): 3-8. ISSN: 0167-5427.
Descriptors: Stenella coeruleoalba, sound reception, deafness, Mediterranean Sea, Spain, stranding record and evidence of deafness.
Aroyan, J.L. (2001). Three-dimensional modeling of hearing in Delphinus delphis. Journal of the Acoustical Society of America 110(6): 3305-18. ISSN: 0001-4966.
Abstract: Physical modeling is a fertile approach to investigating sound emission and reception (hearing) in marine mammals. A method for simulation of hearing was developed combining three-dimensional acoustic propagation and extrapolation techniques with a novel approach to modeling the acoustic parameters of mammalian tissues. Models of the forehead and lower jaw tissues of the common dolphin, Delphinus delphis, were created in order to simulate the biosonar emission and hearing processes. This paper outlines the methods used in the hearing simulations and offers observations concerning the mechanisms of acoustic reception in this dolphin based on model results. These results include: (1) The left and right mandibular fat bodies were found to channel sound incident from forward directions to the left and right tympanic bulla and to create sharp maxima against the lateral surfaces of each respective bulla; (2) The soft tissues of the lower jaw improved the forward directivity of the simulated receptivity patterns; (3) A focal property of the lower-jaw pan bones appeared to contribute to the creation of distinct forward receptivity peaks for each ear; (4) The reception patterns contained features that may correspond to lateral hearing pathways. A "fast" lens mechanism is proposed to explain the focal contribution of the pan bones in this dolphin. Similar techniques may be used to study hearing in other marine mammals.
Descriptors: hearing physiology, models, biological, acoustics, adipose tissue physiology, dolphins, ear physiology, mandible physiology.
Au, W.W. (1996). Acoustic reflectivity of a dolphin. Journal of the Acoustical Society of America 99(6): 3844-8. ISSN: 0001-4966.
Abstract: Backscatter measurements were made on a stationary Atlantic bottlenosed dolphin under controlled conditions. Three sets of measurements were made: (1) broadside aspect target strength as a function of frequency from 23 to 80 kHz; (2) relative target strength as a function of the polar angle about the animal using a short click signal having a peak frequency of 67 kHz; and (3) relative reflective strength of different portions of the animal's body. The mean target strength at the broadside aspect decreased from -11 to -24 dB as the frequency increased from 23 to 45 kHz. As the frequency increased from 45 kHz, the target strength rose to a local maximum of -18 dB at 66 kHz and then decreased to -23 dB at 79 kHz. Maximum target strength was measured at the broadside aspect and exceeded the minimum (tail aspect) target strength by 21 dB. The target strength at the head aspect was 5 dB below that of the broadside aspect. Most acoustic energy was reflected from the area between the dorsal and pectoral fins, corresponding to the location of the dolphin's lungs.
Descriptors: dolphins physiology, sound localization physiology.
Au, W.W., L.N. Andersen, A.R. Rasmussen, H.L. Roitblat, and P.E. Nachtigall (1995). Neural network modeling of a dolphin's sonar discrimination capabilities. Journal of the Acoustical Society of America 98(1): 43-50. ISSN: 0001-4966.
Abstract: The capability of an echolocating dolphin to discriminate differences in the wall thickness of cylinders was previously modeled by a counterpropagation neural network using only spectral information from the echoes. In this study, both time and frequency information were used to model the dolphin discrimination capabilities. Echoes from the same cylinders were digitized using a broadband simulated dolphin sonar signal with the transducer mounted on the dolphin's pen. The echoes were filtered by a bank of continuous constant-Q digital filters and the energy from each filter was computed in time increments of 1/bandwidth. Echo features of the standard and each comparison target were analyzed in pairs by a counterpropagation neural network, a backpropagation neural network, and a model using Euclidean distance measures. The backpropagation network performed better than both the counterpropagation network, and the Euclidean model, using either spectral-only features or combined temporal and spectral features. All models performed better using features containing both temporal and spectral information. The backpropagation network was able to perform better than the dolphins for noise-free echoes with Q values as low as 2 and 3. For a Q of 2, only temporal information was available. However, with noisy data, the network required a Q of 8 in order to perform as well as the dolphin.
Descriptors: dolphins physiology, echolocation physiology, neural networks computer, models, theoretical, noise, transducers.
Au, W.W. and K.J. Benoit Bird (2003). Automatic gain control in the echolocation system of dolphins. Nature (London) 423(6942): 861-863. ISSN: 0028-0836.
NAL Call Number: 472 N21
Abstract: In bats and technological sonars, the gain of the receiver is progressively increased with time after the transmission of a signal to compensate for acoustic propagation loss. The current understanding of dolphin echolocation indicates that automatic gain control is not a part of their sonar system. In order to test this understanding, we have performed field measurements of free-ranging echolocating dolphins. Here we show that dolphins do possess an automatic gain control mechanism, but that it is implemented in the transmission phase rather than the receiving phase of a sonar cycle. We find that the amplitude of the dolphins' echolocation signals are highly range dependent; this amplitude increases with increasing target range, R, in a 20 log(R) fashion to compensate for propagation loss. If the echolocation target is a fish school with many sound scatterers, the echoes from the school will remain nearly constant with range as the dolphin closes in on it. This characteristic has the same effect as time-varying gain in bats and technological sonar when considered from a sonar system perspective.
Descriptors: acoustics, dolphins physiology, echolocation physiology, sound, chiroptera physiology, dolphins classification, hearing physiology, transportation instrumentation, whales physiology.
Notes: Comment In: Nature. 2003 Jun 19;423(6942):815.
Au, W.W. and D.L. Herzing (2003). Echolocation signals of wild Atlantic spotted dolphin (Stenella frontalis). Journal of the Acoustical Society of America 113(1): 598-604. ISSN: 0001-4966.
Abstract: An array of four hydrophones arranged in a symmetrical star configuration was used to measure the echolocation signals of the Atlantic spotted dolphin (Stenella frontalis) in the Bahamas. The spacing between the center hydrophone and the other hydrophones was 45.7 cm. A video camera was attached to the array and a video tape recorder was time synchronized with the computer used to digitize the acoustic signals. The echolocation signals had bi-modal frequency spectra with a low-frequency peak between 40 and 50 kHz and a high-frequency peak between 110 and 130 kHz. The low-frequency peak was dominant when the signal the source level was low and the high-frequency peak dominated when the source level was high. Peak-to-peak source levels as high as 210 dB re 1 microPa were measured. The source level varied in amplitude approximately as a function of the one-way transmission loss for signals traveling from the animals to the array. The characteristics of the signals were similar to those of captive Tursiops truncatus, Delphinapterus leucas and Pseudorca crassidens measured in open waters under controlled conditions.
Descriptors: dolphins physiology, echolocation physiology, signal processing, computer assisted, sound spectrography, Bahamas.
Au, W.W., D.W. Lemonds, S. Vlachos, P.E. Nachtigall, and H.L. Roitblat (2002). Atlantic bottlenose dolphin (Tursiops truncatus) hearing threshold for brief broadband signals. Journal of Comparative Psychology 116(2): 151-157. ISSN: 0735-7036.
Abstract: The hearing sensitivity of an Atlantic bottlenose dolphin (Tursiops truncatus) to both pure tones and broadband signals simulating echoes from a 7.62-cm water-filled sphere was measured. Pure tones with frequencies between 40 and 140 kHz in increments of 20 kHz were measured along with broadband thresholds using a stimulus with a center frequency of 97.3 kHz and 88.2 kHz. The pure-tone thresholds were compared with the broadband thresholds by converting the pure-tone threshold intensity to energy flux density. The results indicated that dolphins can detect broadband signals slightly better than a pure-tone signal. The broadband results suggest that an echolocating bottlenose dolphin should be able to detect a 7.62-cm diameter water-filled sphere out to a range of 178 m in a quiet environment.
Descriptors: auditory threshold, dolphins psychology, echolocation, pitch discrimination, appetitive behavior, psychoacoustics, sound spectrography.
Au, W.W., P.E. Nachtigall, and J.L. Pawloski (1997). Acoustic effects of the ATOC signal (75 Hz, 195 dB) on dolphins and whales. Journal of the Acoustical Society of America 101(5, Pt. 1): 2973-7. ISSN: 0001-4966.
Abstract: The Acoustic Thermometry of Ocean Climate (ATOC) program of Scripps Institution of Oceanography and the Applied Physics Laboratory, University of Washington, will broadcast a low-frequency 75-Hz phase modulated acoustic signal over ocean basins in order to study ocean temperatures on a global scale and examine the effects of global warming. One of the major concerns is the possible effect of the ATOC signal on marine life, especially on dolphins and whales. In order to address this issue, the hearing sensitivity of a false killer whale (Pseudorca crassidens) and a Risso's dolphin (Grampus griseus) to the ATOC sound was measured behaviorally. A staircase procedure with the signal levels being changed in 1-dB steps was used to measure the animals' threshold to the actual ATOC coded signal. The results indicate that small odontocetes such as the Pseudorca and Grampus swimming directly above the ATOC source will not hear the signal unless they dive to a depth of approximately 400 m. A sound propagation analysis suggests that the sound-pressure level at ranges greater than 0.5 km will be less than 130 dB for depths down to about 500 m. Several species of baleen whales produce sounds much greater than 170-180 dB. With the ATOC source on the axis of the deep sound channel (greater than 800 m), the ATOC signal will probably have minimal physical and physiological effects on cetaceans.
Descriptors: acoustics, auditory perception physiology, dolphins, echolocation physiology, whales.
Au, W.W., J.L. Pawloski, P.E. Nachtigall, M. Blonz, and R.C. Gisner (1995). Echolocation signals and transmission beam pattern of a false killer whale (Pseudorca crassidens). Journal of the Acoustical Society of America 98(1): 51-9. ISSN: 0001-4966.
Abstract: The echolocation transmission beam pattern of a false killer whale (Pseudorca crassidens) was measured in the vertical and horizontal planes. A vertical array of seven broadband miniature hydrophones was used to measure the beam pattern in the vertical plane and a horizontal array of the same hydrophones was used in the horizontal plane. The measurements were performed in the open waters of Kaneohe Bay, Oahu, Hawaii, while the whale performed a target discrimination task. Four types of signals, characterized by their frequency spectra, were measured. Type-1 signals had a single low-frequency peak at 40 +/- 9 kHz and a low-amplitude shoulder at high frequencies. Type-2 signals had a bimodal frequency characteristic with a primary peak at 46 +/- 7 kHz and a secondary peak at 88 +/- 13 kHz. Type-3 signals were also bimodal but with a primary peak at 100 +/- 7 kHz and a secondary peak at 49 +/- 9 kHz. Type-4 signals had a single high-frequency peak at 104 +/- 7 kHz. The center frequency of the signals were found to be linearly correlated to the peak-to-peak source level, increasing with increasing source level. The major axis of the vertical beam was directed slightly downward between 0 and -5 degrees, in contrast to the +5 to 10 degrees for Tursiops and Delphinapterus. The beam in the horizontal plane was directed forward between 0 degrees and -5 degrees.
Descriptors: echolocation physiology, whales physiology, models, theoretical.
Au, W.W.L. (2003). A comparison of the sonar capabilities of bats and dolphins. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, xiii-xxvii p. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Odontoceti, echolocation, sonar capabilities, comparison with Chiroptera.
Au, W.W.L., L.N. Andersen, A.R. Rasmussen, H.L. Roitblat, and P.E. Nachtigall (1995). Neural network modeling of a dolphin's sonar discrimination capabilities. Journal of the Acoustical Society of America 98(1): 43-50. ISSN: 0001-4966.
Descriptors: nervous system, neural coordination, sense organs, sensory reception.
Au, W.W.L., J.K.B. Ford, J.K. Horne, and K.A. Newman Allman (2004). Echolocation signals of free-ranging killer whales (Orcinus orca) and modeling of foraging for chinook salmon (Oncorhynchus tshawytscha). Journal of the Acoustical Society of America 115(2): 901-909. ISSN: 0001-4966.
Abstract: Fish-eating "resident" -type killer whales (Orcinus orca) that frequent the coastal waters off northeastern Vancouver Island, Canada have a strong preference for chinook salmon (Oncorhynchus tshawytscha). The whales in this region often forage along steep cliffs that extend into the water, echolocating their prey. Echolocation signals of resident killer whales were measured with a four-hydrophone symmetrical star array and the signals were simultaneously digitized at a sample rate of 500 kHz using a lunch-box PC. A portable VCR recorded the images from an underwater camera located adjacent to the array center. Only signals emanating from close to the beam axis (1185 total) were chosen for a detailed analysis. Killer whales project very broadband echolocation signals (Q equal 0.9 to 1.4) that tend to have bimodal frequency structure. Ninety-seven percent of the signals had center frequencies between 45 and 80 kHz with bandwidths between 35 and 50 kHz. The peak-to-peak source level of the echolocation signals decreased as a function of the one-way transmission loss to the array. Source levels varied between 195 and 224 dB re:1 [mu]Pa. Using a model of target strength for chinook salmon, the echo levels from the echolocation signals are estimated for different horizontal ranges between a whale and a salmon. At a horizontal range of 100 m, the echo level should exceed an Orcinus hearing threshold at 50 kHz by over 29 dB and should be greater than sea state 4 noise by at least 9 dB. In moderately heavy rain conditions, the detection range will be reduced substantially and the echo level at a horizontal range of 40 m would be close to the level of the rain noise.
Descriptors: Oncorhynchus tshawytscha, mammalian predators, Orcinus orca, echolocation by predator, North Pacific, Canada, British Columbia, Vancouver Island, echolocation by mammalian predator, modelling.
Au, W.W.L., A.N. Popper and R.R. Fay (Editors) (2000). Hearing by Whales and Dolphins, Springer Handbook of Auditory Research, Springer: New York, 485 p. ISBN: 0387949062.
NAL Call Number: QL737.C432 H43 2000
Descriptors: dolphins, physiology, whales, hearing.
Aubauer, R. and W.W. Au (1998). Phantom echo generation: a new technique for investigating dolphin echolocation. Journal of the Acoustical Society of America 104(3, Pt. 1): 1165-70. ISSN: 0001-4966.
Abstract: In behavioral experiments where real targets are used to investigate dolphin echolocation, it is often very difficult to extract the relevant echo parameters that the animals use to discriminate or classify. The complex relationship between the physical dimensions and the reflection characteristic of real targets prevents separate control of various echo parameters of the stimuli presented in an echolocation experiment. A new echo simulation method presented in this paper avoids this problem. Dolphin echolocation sounds are transformed with the target impulse response into artificial echoes, which are played back to the animal. The phantom echo system is implemented on a digital signal processing board and gives an experimenter fully programmable control over the echo generating process and the echo structure itself. Echoes of several underwater targets were simulated to evaluate the quality of the method. A comparison of simulated echoes with the original echoes demonstrated very good agreement independent of the incident signal (cross-correlation coefficient > 0.95). The method has tremendous potential for investigating animal echolocation and understanding biosonar signal processing.
Descriptors: acoustic stimulation methods, echolocation physiology, porpoises physiology, models, biological.
Aubauer, R., M.O. Lammers, and W.W. Au (2000). One-hydrophone method of estimating distance and depth of phonating dolphins in shallow water. Journal of the Acoustical Society of America 107(5, Pt. 1): 2744-9. ISSN: 0001-4966.
Abstract: Previous attempts at localizing cetaceans have generally used multiple hydrophone arrays and multichannel recording systems. In this paper, a low-budget localization technique using only one hydrophone is described. The time delays of the signals traveling via the surface and bottom reflection paths to the hydrophone, relative to the direct signal, are used to calculate the distance and the depth of a phonating animal. Only two additional measures, the depth of the bottom and hydrophone, have to be taken. The method requires relatively shallow waters and a flat bottom surface. Echolocating and burst pulsing Hawaiian spinner dolphins (Stenella longirostris) at the Waianae coast of Oahu, Hawaii, were localized over different bottom substrates. A tracking range of up to 100 m was achieved. The accuracy of the method is estimated by the total error differential technique. The relative distance estimation error is below 35% and the absolute depth error below 0.7 m, so that the location method is sufficiently precise for examining source levels in our study area. Because of its simplicity, the method ideally complements sound recordings and visual sightings of marine mammals and could lead to a better understanding of the nature and use of click trains by dolphins.
Descriptors: animal communication, phonation physiology, dolphins, echolocation physiology, models, biological, water.
Aubauer, R., W.W.L. Au and P.E. Nachtigall (2003). Acoustic simulation of phantom target echoes in dolphin behavioral experiments. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 514-518. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Odontoceti, behavioral techniques, acoustic simulation of phantom target echoes in echolocation experiments, echolocation.
Babushina, E.S. (1999). Zvukovaia retseptsiia morskikh mlekopitaiushchikh v zavisimosti ot parametrov i putei provedeniia zvuka. [Sound reception of marine mammales depending on parameters and sound-conducting tracks]. Biofizika 44(6): 1101-8. ISSN: 0006-3029.
Abstract: The interaction of complex sounds with the body tissues of Black Sea dolphin (Tursiops truncatus) was studied by the method of instrumental conditioned reflexes with food reinforcement. The thresholds of detecting underwater acoustic signals of different frequencies for dolphin and northern fur seal (Callorhinus ursinus) were measured as a function of pulse duration under conditions of full and partial (head above water) submergence of animals into water. It was found that sound conduction through dolphin tissues was more effective than that in a northern fur seal in a wide frequency range. Presumably, the process of sound propagation in dolphin is accompanied by changes in the amplitude-frequency structure of broad-band sounds. The temporal summation in dolphin hearing was observed at all frequencies under conditions of full and partial submergence, whereas in northern fur seal it was nearly absent at a frequency of 5 kHz under the conditions of head lifting above water.
Descriptors: dolphins physiology, hearing physiology, seals, earless physiology, sound localization physiology, acoustic stimulation, auditory threshold, conditioning, operant physiology.
Language of Text: Russian.
Babushina, E.S. and M.A. Polyakov (2003). Frequency discrimination by Black Sea bottle-nosed dolphin and northern fur seal depending on sound parameters and sound conduction pathways. Biofizika 48(2): 332-336. ISSN: 0006-3029.
Descriptors: Callorhinus ursinus, Tursiops truncatus, sound reception, frequency discrimination, underwater sound frequency and conduction pathway significance, conditioning, sound, frequency and conduction.
Babushkina, E.S. (2001). Osobennosti zvukoprovedeniia u mlekopitaiushchikh v vodnoi srede. [Characteristics of the sound conduction in mammals in the aqueous medium]. Biofizika 46(1): 80-7. ISSN: 0006-3029.
Abstract: Experimental investigations of sound-conducting tracts in man, seals and dolphins are reviewed. Underwater hearing is considered in connection with anatomical, morphological, and functional features of species and ecological factors.
Descriptors: auditory perception physiology, mammals physiology, sense organs physiology, water chemistry, ear anatomy and histology, ear physiology.
Language of Text: Russian.
Babushkina, E.S. and M.A. Poliakov (2003). Chastotnoe razlichenie v slukhe del'fina afaliny i severnogo morskogo kotika v zavisimosti ot parametrov i putei provedeniia zvuka. [Frequency discrimination by the bottle-nosed dolphin and the Northern fur seal depending on sound parameters and sound conduction pathways]. Biofizika 48(2): 332-6. ISSN: 0006-3029.
Abstract: Underwater differential frequency hearing thresholds in the Black Sea bottle-nosed dolphin (Tursiops truncatus sp.) and the northern fur seal (Callorhinus ursinus) were measured depending on signal frequency and sound conduction pathways. The measurements were performed by the method of instrumental conditioned reflexes with food reinforcement under conditions of full and partial (with heads out of water at sound conduction through body tissues) submergence of animals into water. It was shown that in a frequency range of 5-100 kHz, underwater differential frequency hearing thresholds of the bottle-nosed dolphin changed from 0.46-0.60% to 0.21-0.34% and depended little on sound conduction pathways. The minimum underwater differential frequency hearing thresholds of the northern fur seal corresponded to the frequencies of maximum hearing sensitivity, changed from 1.7% to 1-2.3% in a frequency range of 1-20 kHz, sharply increased at the edges of the frequency hearing perception range, and depended little (in a range of 5-40 kHz) on sound conduction pathways. Thus, underwater sounds propagating through the body tissues of dolphin and fur seal reach the inner ear.
Descriptors: auditory perception, dolphins physiology, fur seals physiology, auditory pathways, auditory threshold, conditioning, operant, immersion.
Language of Text: Russian.
Bain, D.E. and M.E. Dahlheim (1994). Effects of masking noise on detection thresholds of killer whales. In: Marine Mammals and the Exxon Valdez, Academic Press, Inc.: San Diego, California, USA; London, England, UK, p. 243-264. ISBN: 0124561608.
Descriptors: behavior, biochemistry and molecular biophysics, communication, marine ecology, environmental sciences, pollution assessment control and management, wildlife management, conservation, animal communication, echolocation, Exxon Valdez oil spill, Prince William Sound.
Barham, E.G. (1973). Whales' respiratory volume as a possible resonant receiver for 20 Hz signals. Nature (London) 245(5422): 220-221. ISSN: 0028-0836.
NAL Call Number: 472 N21
Abstract: Since the advent, some 25 yr ago, of recording equipment responsive over a wide frequency band, listening stations at scattered ocean locations have recorded long, repetitious trains of powerful, low frequency sound pulses that vary over a narrow 6 Hz band centred at about 20 Hz(1,2). Once an enigma, the source of these remarkable signals is now thought to be baleen whales, and although several types of signals have been recorded(3), implying that more than one species is responsible, strong evidence implicates the finback whale, Balaenoptera physalus, as one of the generators(1). The low frequency acoustic mechanisms of whales are as yet unknown(4) but, based mainly on sound propagation theory, it has been both suggested(2,4) and vigorously argued(5) that the whales use the signals for long-range communication.
Descriptors: frequency, band, sound pulses, whales, acoustics, long-range, communication, baleen whales, finback whale.
Barlow, J. and G.A. Cameron (2003). Field experiments show that acoustic pingers reduce marine mammal bycatch in the California drift gill net fishery. Marine Mammal Science 19(2): 265-283. ISSN: 0824-0469.
NAL Call Number: QL713.2.M372
Descriptors: Pinnipedia, Cetacea, fishing and fisheries, conservation measures, mortality, north Pacific, USA, California, fishery bycatch reduction using acoustic pingers, evaluation.
Barrett Lennard, L.G., J.K.B. Ford, and K.A. Heise (1996). The mixed blessing of echolocation: differences in sonar use by fish-eating and mammal-eating killer whales. Animal Behaviour 51(3): 553-565. ISSN: 0003-3472.
NAL Call Number: 410 B77
Descriptors: Orcinus orca, echolocation, sound patterns, food habit relationship, Alaska, British Columbia, mammalian prey, sonar sounds comparison with piscean prey foraging populations, Piscean prey, sonar sounds comparison with mammalian prey foraging populations, north Pacific, feeding behavior, food habits and echolocation sound patterns relationship, behavioral variation, echolocation patterns, Canada, USA, echolocation sounds, comparison of populations with divergent food habits.
Bazua Duran, C. (2004). Differences in the whistle characteristics and repertoire of bottlenose and spinner dolphins. Anais Da Academia Brasileira De Ciencias 76(2): 386-92. ISSN: 0001-3765.
Abstract: Several methods have been used to compare the whistles produced by dolphins. The two methods used in this study are: (1) a classification of whistle contours in six categories (i.e. constant frequency, upsweep, downsweep, concave, convex, and sine) and (2) the extraction of frequency and time parameters from each whistle contour. Bottlenose Dolphin Tursiops truncatus whistles are described in the same way when comparing whistle contour distributions in each of the six categories and whistle frequency and time parameters using Discriminant Function Analysis. For Spinner Dolphin Stenella longirostris whistles, each method describes whistles differently. Several facts may explain these differences in describing dolphin whistles, such as a greater fluidity of Spinner Dolphin groups when compared to Bottlenose Dolphin groups, greater geographic variation in the whistles of Bottlenose Dolphins than in those of Spinner Dolphins, an average beginning frequency 16% lower than the average ending frequency in Spinner Dolphin whistles compared to a varied relationship for Bottlenose Dolphins, and stricter criteria used to define whistle contour categories in the study of Spinner Dolphin whistles than in the Bottlenose Dolphin whistle study.
Descriptors: dolphins physiology, vocalization, animal classification, sound spectrography, species specificity.
Bazua Duran, C. and W.W.L. Au (2004). Geographic variations in the whistles of spinner dolphins (Stenella longirostris) of the Main Hawai'ian Islands. Journal of the Acoustical Society of America 116(6): 3757-3769. ISSN: 0001-4966.
Descriptors: Stenella longirostris, behavioral variation, acoustic signals, whistles, north Pacific, Hawaii, whistle vocalizations, geographic variation.
Bazua Duran, C. and W.W.L. Au (2002). The whistles of Hawaiian spinner dolphins. Journal of the Acoustical Society of America 112(6): 3064-3072. ISSN: 0001-4966.
Descriptors: Stenella longirostris, acoustic signals, whistles, repertoire and frequency, north Pacific, Hawaii, whistle repertoire and frequency.
Benoit Bird, K.J., B. Wuersig, and C.J. McFadden (2004). Dusky dolphin (Lagenorhynchus obscurus) foraging in two different habitats: active acoustic detection of dolphins and their prey. Marine Mammal Science 20(2): 215-231. ISSN: 0824-0469.
NAL Call Number: QL713.2.M372
Abstract: Active-acoustic surveys were used to determine the distribution of dusky dolphins and potential prey in two different New Zealand locations. During seven survey days off Kaikoura Canyon, dusky dolphins were found within the Deep-Scattering Layer (DSL) at 2000 when it rose to within 125 m of the surface. As the DSL rose to 30 m at 0100, the observed depth of dolphins decreased, presumably as the dolphins followed the vertical migration of their prey. acoustically identified subgroups of coordinated animals ranged from one to five dolphins. Time, depth of layer, and layer variance contributed significantly to predicting foraging dusky dolphin subgroup size. In the much shallower and more enclosed Admiralty Bay, dolphins noted at the surface as foraging were always detected with the sonar, but were never observed in coordinated subgroups during the brief (two-day) study there. In Admiralty Bay dolphin abundance was correlated with mean volume scattering from potential prey in the water column; and when volume scattering, an index of prey density, was low, dolphins were rarely present. Ecological differences between the deep waters of Kaikoura Canyon and the shallow nearshore waters of Admiralty Bay may result in differences in how, when, and in what social groupings dusky dolphins forage.
Descriptors: Lagenorhynchus obscurus, foraging, deep and shallow waters, social behavior, ecology, South Pacific, New Zealand, Admiralty Bay and Kaikoura Canyon, foraging strategy, active acoustic analysis.
Blomqvist, C. and M. Amundin (2004). An acoustic tag for recording directional pulsed ultrasounds aimed at free-swimming bottlenose dolphins (Tursiops truncatus) by conspecifics. Aquatic Mammals 30(3): 345-356. ISSN: 0167-5427.
Abstract: We developed an acoustic tag, called MOSART (Mobile Submersible Acoustic Recorder of Transients), for recording directional social pulses produced by a bottlenose dolphin (Tursiops truncatus). The tag was attached to the dorsal fin of two dolphins by means of suction cups. Two adult bottlenose dolphins at the Kolmardens Djurpark, Sweden, were trained to carry the tag comfortably through a desensitising program. The tag included two envelope click-detectors, each with a narrow bandpass filter, centred at 120 and 70 kHz, respectively. The duration of the original pulses and their relative amplitude within the two filter frequency bands was retained. The amplitude differences between the two filter bands reflected changes in the source frequency spectrum and/or the position of the tag hydrophone in the incoming sound beam. The tag recorded "echolocation click trains," "slow and irregular pulses," and "pulse bursts" with varying amounts of energy in both frequency bands. The peak amplitude and duration of clicks in "echolocation click trains" and in "slow and irregular pulses" were logged correctly; however, the tag recorder had more difficulties in handling the complex pulses in the aggressive "pulse bursts," where the duration of the individual pulses could not be determined. Still, the amplitude and the pulse repetition rate could be measured. The possible impact of the tag was investigated by analysing the dolphin's behaviours (12 categories), sounds (3 categories), preferred location in the pool, and respiration intervals. Only four of the behaviours and one preferred location in the pool showed significant differences among pre-tag baselines, tag periods, and post-tag follow-ups, suggesting that the tag had only a minor impact on the dolphin. We describe and discuss the tag and its capacity to record different pulsed sounds.
Descriptors: Tursiops truncatus, sound recording techniques, social pulsed ultrasound recording technique using acoustic tag, telemetry techniques, echolocation, directional pulsed ultrasounds.
Blomqvist, C. and M. Amundin (2003). High-frequency burst-pulse sounds in agonistic/aggressive interactions in bottlenose dolphins, Tursiops truncatus. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 425-431. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Tursiops truncatus, echolocation, agonistic behavior, acoustic signals, high frequency burst pulse sounds characterization during agonistic interactions.
Boisseau, O. (2005). Quantifying the acoustic repertoire of a population: the vocalizations of free-ranging bottlenose dolphins in Fiordland, New Zealand. Journal of the Acoustical Society of America 117(4): 2318-2329; (Pt. 1). ISSN: 0001-4966.
Descriptors: Tursiops truncatus, acoustic signals, south Pacific, New Zealand, Fiordland, vocalizations, acoustic repertoire quantification.
Branstetter, B.K., S.J. Mevissen, L.M. Herman, A.A. Pack, and S.P. Roberts (2003). Horizontal angular discrimination by an echolocating bottlenose dolphin Tursiops truncatus. Bioacoustics 14(1): 15-34. ISSN: 0952-4622.
Descriptors: Tursiops truncatus, echolocation, horizontal angular discrimination.
Braun, M. (1994). Tuned hair cells for hearing, but tuned basilar membrane for overload protection: evidence from dolphins, bats, and desert rodents. Hearing Research 78(1): 98-114. ISSN: 0378-5955.
Abstract: A cochlear model is presented suggesting that the organ of Corti (OC) and the basilar membrane (BM) are both tuned resonant systems, but have different functions. The OC provides frequency filtering and amplification by means of tuned outer hair cells. The BM provides resonant absorption of excessive vibrational energy as an overload protection for vulnerable elements in the OC. Evidence supporting this model is demonstrated in dolphins, bats, and desert rodents. Specialized auditory capabilities correlate with cochlear deviations, some of them dramatically changing BM compliance. In characteristic regions along the cochlea there are BM thickenings and, on both sides of the OC, hypertrophied supporting cells. Structures of striking similarity have evolved independently across orders or families, revealing multiple events of convergent evolution. In all cases, the locations of deviating structures rule out a BM function in auditory frequency selectivity but support one in resonant absorption. Cochlear microphonics and BM responses demonstrate strongest high-level absorption in the frequency bands most vital for the tested species. The assumed cause is increased internal damping in the enlarged structures during BM motion. Species with intermediate specializations supply further evidence that resonant absorption is universally the genuine function of BM mechanics in mammals, providing complementary high-level protection of low-level sensitivity.
Descriptors: auditory threshold physiology, basilar membrane physiology, mammals physiology, organ of corti physiology, absorption, acoustic stimulation, basilar membrane anatomy and histology, Chiroptera physiology, dolphins physiology, hair cells, outer physiology, models, biological, Rodentia physiology.
Brill, R.L., P.W. Moore, and L.A. Dankiewicz (2001). Assessment of dolphin (Tursiops truncatus) auditory sensitivity and hearing loss using jawphones. Journal of the Acoustical Society of America 109(4): 1717-22. ISSN: 0001-4966.
Abstract: Devices known as jawphones have previously been used to measure interaural time and intensity discrimination in dolphins. This study introduces their use for measuring hearing sensitivity in dolphins. Auditory thresholds were measured behaviorally against natural background noise for two bottlenose dolphins (Tursiops truncatus); a 14-year-old female and a 33-year-old male. Stimuli were delivered to each ear independently by placing jawphones directly over the pan bone of the dolphin's lower jaw, the assumed site of best reception. The shape of the female dolphin's auditory functions, including comparison measurements made in the free field, favorably matches that of the accepted standard audiogram for the species. Thresholds previously measured for the male dolphin at 26 years of age indicated a sensitivity difference between the ears of 2-3 dB between 4-10 kHz, which was considered unremarkable at the time. Thresholds for the male dolphin reported in this study suggest a high-frequency loss compared to the standard audiogram. Both of the male's ears have lost sensitivity to frequencies above 55 kHz and the right ear is 16-33 dB less sensitive than the left ear over the 10-40 kHz range, suggesting that males of the species may lose sensitivity as a function of age. The results of this study support the use of jawphones for the measurement of dolphin auditory sensitivity.
Descriptors: auditory perception physiology, dolphins physiology, hearing aids, hearing disorders diagnosis, jaw, audiometry methods, noise, sensitivity and specificity.
Buck, J.R., H.B. Morgenbesser, and P.L. Tyack (2000). Synthesis and modification of the whistles of the bottlenose dolphin, Tursiops truncatus. Journal of the Acoustical Society of America 108(1): 407-16. ISSN: 0001-4966.
Abstract: A signal-processing algorithm was developed to analyze harmonic frequency-modulated sounds, to modify the parameters of the analyzed signal, and to synthesize a new analytically specified signal that resembles the original signal in specified features. This algorithm was used with dolphin whistles, a frequency-modulated harmonic signal that has typically been described in terms of its contour, or pattern of modulation of the fundamental frequency. In order to test whether other features may also be salient to dolphins, the whistle analysis calculates the energies at the harmonics as well as the fundamental frequency of the whistle. The modification part of the algorithm can set all of these energies to a constant, can shift the whistle frequency, and can expand or compress the time base or the frequency of the whistle. The synthesis part of the algorithm then synthesizes a waveform based upon the energies and frequencies of the fundamental and first two harmonics. These synthetic whistles will be useful for evaluating what acoustic features dolphins use in discriminating different whistles.
Descriptors: algorithms, vocalization, animal physiology, dolphins physiology, models, biological.
Carlstrom, J. (2005). Diel variation in echolocation behavior of wild harbor porpoises. Marine Mammal Science 21(1): 1-12. ISSN: 0824-0469.
NAL Call Number: QL713.2.M372
Abstract: echolocation rate and behavior of wild harbor porpoises were studied using a harbor porpoise click detector (POD) deployed close to the bottom at 40 in depth in Scottish waters, UK, April-June 2001. Echolocation variables were compared among four diel phases; morning, day, evening, and night. The echolocation encounter rate, the minimum interclick interval per train, and the proportion of echolocation click trains with a minimum interclick interval below 10 msec were all significantly higher at night than during the day. The variation in echolocation rate implies that porpoises increased their echolocation rate and/or visited the depth of the POD more often at night than during the day. Further, the changes in minimum interclick interval per train suggest that they used their echolocation for foraging or investigating objects at a close range to a higher extent, and acoustically explored the environment at greater distances at night than during the day.
Descriptors: Phocoena phocoena, echolocation, diel behavior patterns, circadian activity, diel echolocation behavior patterns, North Atlantic, United Kingdom, Scotland, Hebrides, Mull, Bloody Bay, echolocation behavior, diel patterns.
Cherbit, G. and G. Alcuri (1978). Etude de la propagation des vibrations a travers le rostre de Sotalia teuzii [Cetacea] par interferometrie holographique [Odontocetes]. [Interferometric study of the propagation of vibrations through the rostrum of Sotalia teuzii [Cetacean Odontocetes]]. Comptes Rendus Hebdomadaires Des Seances De L'Academie Des Sciences. Serie D. Sciences Naturelles 286(8): 607-610. ISSN: 0567-655X.
Descriptors: vibrations, rostrum, propagation, study, Sotalia teuzii, odontocetes.
Language of Text: English and French summaries.
Ciaramitaro, S., M. Azzali, S. Catacchio, M. Jones, R. Simoni, and A. Ruggeri (2000). The evolution of the acoustic and social behaviour in an artificial community of dolphins. European Research on Cetaceans 14: 81-85. ISSN: 1028-3412.
Descriptors: Tursiops truncatus, acoustic signals, social behavior, evolution in artificial community.
Clark, C.W. and P.J. Clapham (2004). Acoustic monitoring on a humpback whale (Megaptera novaeangliae) feeding ground shows continual singing into late spring. Proceedings of the Royal Society of London. Series B. Biological Sciences 271(1543): 1051-1057. ISSN: 0962-8452.
Abstract: Singing by males is a major feature of the mating system of humpback whales, Megaptera novaeangliae (Borowski). Although a few songs have been opportunistically recorded on the whales' high-latitude feeding grounds, singing in these regions was thought to be only sporadic. We report results from the first continuous acoustic monitoring of a humpback whale feeding ground (off Cape Cod, MA, USA) in spring. Using autonomous sea-floor recording systems, we found singing on a daily basis over the entire 25 day monitoring period, from 14 May to 7 June 2000. For much of the period, song was recorded 24 h per day. These results, combined with evidence for aseasonal conceptions in whaling catch data, suggest that the humpback whale breeding season. should no longer be considered as confined to lower-latitude regions in winter. Rather, we suggest breeding extends geographically and temporally onto feeding grounds into at least spring and early summer. Singing at these times represents either low-cost opportunistic advertising by (perhaps relatively few) males to court females that failed to conceive during the winter, and/or possibly an intrasexual display.
Descriptors: Megaptera novaeangliae, breeding season, courtship, acoustic signals, intraspecific competition, North Atlantic, USA, Massachusetts, continual singing at feeding ground, implications for breeding season.
Clark, C.W. and W.T. Ellison (2003). Potential use of low-frequency sounds by baleen whales for probing environment: evidence from models and empirical measurements. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 564-582. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: mysticeti, sound reception, hearing thresholds, review, biosonar implications, echolocation, potential use of low frequency sounds for environment probing, models and empirical measurements, acoustic signals, characterization in shallow and deep waters, long range communication and biosonar potential, orientation.
Clarke, M.R. (2003). Production and control of sound by the small sperm whales, Kogia breviceps and K. sima and their implications for other Cetacea. Journal of the Marine Biological Association of the United Kingdom 83(2): 241-263. ISSN: 0025-3154.
NAL Call Number: 442.9 M331
Descriptors: communication, respiratory system, respiration, buoyancy, sound control, sound production, thermal properties, Kogia, Cetacea.
Cook, M.L., L.S. Sayigh, J.E. Blum, and R.S. Wells (2004). Signature-whistle production in undisturbed free-ranging bottlenose dolphins (Tursiops truncatus). Proceedings of the Royal Society of London. Series B. Biological Sciences 271(1543): 1043-1049. ISSN: 0962-8452.
Abstract: Data from behavioural observations and acoustic recordings of free-ranging bottlenose dolphins (Tursiops truncatus) were analysed to determine whether signature whistles are produced by wild undisturbed dolphins, and how whistle production varies with activity and group size. The study animals were part of a resident community of bottlenose dolphins near Sarasota, Florida, USA. This community of dolphins provides a unique opportunity for the study of signature-whistle production, since most animals have been recorded during capture-release events since 1975. Three mother-calf pairs and their associates were recorded for a total of 141.25 h between May and August of 1994 and 1995. Whistles of undisturbed dolphins were compared with those recorded from the same individuals during capture-release events. Whistles were conservatively classified into one of four categories: signature, probable signature, upsweep or other. For statistical analyses, signature and probable signature whistles were combined into a 'signature' category; upsweep and other whistles were combined into a 'non-signature' category. Both 'signature' and 'non-signature' whistle frequencies significantly increased as group size increased. There were significant differences in whistle frequencies across activity types: both 'signature' and 'non-signature' whistles were most likely to occur during socializing and least likely to occur during travelling. There were no significant interactions between group size and activity type. Signature and probable signature whistles made up ca. 52% of all whistles produced by these free-ranging bottlenose dolphins.
Descriptors: Tursiops truncatus, acoustic signals, observations on undisturbed free ranging animals, schooling, group size, Gulf of Mexico, USA, Florida, Sarasota, signature whistle production, activity and group size relationships, undisturbed wild animals.
Cox, T.M. and A.J. Read (2004). Echolocation behavior of harbor porpoises Phocoena phocoena around chemically enhanced gill nets. Marine Ecology Progress Series 279: 275-282. ISSN: 0171-8630.
NAL Call Number: QH541.5.S3M32
Abstract: The echolocation behavior of harbor porpoises Phocoena phocoena around gillnets was monitored to test their response to chemically (BaSO4) enhanced gill nets, designed to be more acoustically reflective than commercial nets. Field trials were conducted. between 22 July and 31 August 2000 in the Bay of Fundy, Canada. Echolocation clicks were continuously monitored with Porpoise Echolocation Detectors (PODs). Commercial and experimental (chemically enhanced) gill nets were set for groundfish in water depths from 100 to 130 m. Echolocation occurrence (the proportion of 10 s intervals during which clicks were detected) and echolocation rate (the number of clicks h-1) were measured. The PODs varied in their detection ability, so comparisons between commercial and enhanced nets were made with individual PODs. Neither echolocation rate nor occurrence differed with net type for any POD. Significantly more echolocation was detected during the day than at night. Echolocation rate and echolocation occurrence varied with depth and location, possibly reflecting concomitant variation in the relative abundance of porpoises and/or their prey: We conclude that porpoises do not respond to the acoustic reflectivity of the modified nets. Rather, the effectiveness of these nets is apparently due to other factors, such as their physical properties, particularly their stiffness.
Descriptors: Phocoena phocoena, fishing and fisheries, chemically enhanced gill nets, echolocation, behavior around chemically enhanced gill nets, acoustic signals, north Atlantic, Canada, Bay of Fundy, echolocation behavior around chemically enhanced gill nets.
Crail, T. (1981). Apetalk & Whalespeak: the Quest for Interspecies Communication, 1st edition, J.P. Tarcher; distributed by Houghton Mifflin: Los Angeles, Boston, 298 p. ISBN: 0874771803.
NAL Call Number: QL776.C7 1981
Descriptors: human animal communication.
Cranford, T.W. and M. Amundin (2003). Biosonar pulse production in Odontocetes: the state of our knowledge. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 27-35. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Odontoceti, echolocation, biosonar pulse production, review.
Croll, D.A., C.W. Clark, A. Acevedo, B. Tershy, S. Flores, J. Gedamke, and J. Urban (2002). Only male fin whales sing loud songs. Nature (London) 417(6891): 809. ISSN: 0028-0836.
NAL Call Number: 472 N21
Abstract: The low-frequency vocalizations of fin and blue whales are the most powerful and ubiquitous biological sounds in the ocean. Here we combine acoustic localization and molecular techniques to show that, in fin whales, only males produce these vocalizations. This finding indicates that they may function as male breeding displays, and will help to focus concern on the impact of human-generated low-frequency sounds on recovering whale populations.
Descriptors: sex characteristics, vocalization, animal physiology, whales physiology, ecosystem, sex behavior, animal physiology, sex ratio.
Dawson, S.M. and D. Lusseau (2005). Pseudoreplication problems in studies of dolphin and porpoise reactions to pingers. Marine Mammal Science 21(1): 175-176. ISSN: 0824-0469.
NAL Call Number: QL713.2.M372
Descriptors: Odontoceti, mathematical techniques, statistical analysis, reactions to pingers on gill nets, pseudoreplication problems, avoidance behavior.
Deecke, V.B., J.K. Ford, and P. Spong (1999). Quantifying complex patterns of bioacoustic variation: use of a neural network to compare killer whale (Orcinus orca) dialects. Journal of the Acoustical Society of America 105(4): 2499-507. ISSN: 0001-4966.
Abstract: A quantitative measure of acoustic similarity is crucial to any study comparing vocalizations of different species, social groups, or individuals. The goal of this study was to develop a method of extracting frequency contours from recordings of pulsed vocalizations and to test a nonlinear index of acoustic similarity based on the error of an artificial neural network at classifying them. Since the performance of neural networks depends on the amount of consistent variation in the training data, this technique can be used to assess such variation from samples of acoustic signals. The frequency contour extraction and the neural network index were tested on samples of one call type shared by nine social groups of killer whales. For comparison, call similarity was judged by three human subjects in pairwise classification tasks. The results showed a significant correlation between the neural network index and the similarity ratings by the subjects. Both measures of acoustic similarity were significantly correlated with the groups' association patterns, indicating that both methods of quantifying acoustic similarity are biologically meaningful. An index based on neural network analysis therefore represents an objective and repeatable means of measuring acoustic similarity, and allows comparison of results across studies, species and time.
Descriptors: animal communication, nerve net physiology, porpoises physiology, acoustics, models, biological.
Ding, W., B. Wursig, and S. Leatherwood (2001). Whistles of boto, Inia geoffrensis, and tucuxi, Sotalia fluviatilis. Journal of the Acoustical Society of America 109(1): 407-11. ISSN: 0001-4966.
Abstract: Whistles were recorded and analyzed from free-ranging single or mixed species groups of boto and tucuxi in the Peruvian Amazon, with sonograms presented. Analysis revealed whistles recorded falling into two discrete groups: a low-frequency group with maximum frequency below 5 kHz, and a high-frequency group with maximum frequencies above 8 kHz and usually above 10 kHz. Whistles in the two groups differed significantly in all five measured variables (beginning frequency, end frequency, minimum frequency, maximum frequency, and duration). Comparisons with published details of whistles by other platanistoid river dolphins and by oceanic dolphins suggest that the low-frequency whistles were produced by boto, the high-frequency whistles by tucuxi. Tape recordings obtained on three occasions when only one species was present tentatively support this conclusion, but it is emphasized that this is based on few data.
Descriptors: animal communication, dolphins, sound spectrography, vocalization, animal, species specificity.
Dobbins, P.F. (2001). Modelling dolphin echolocation reception. Proceedings of the Institute of Acoustics 23(4): 123-132. ISSN: 0309-8117.
Descriptors: Tursiops truncatus, teeth, echolocation, reception modelling, possible role of teeth.
Dolphin, W.F., W.W.L. Au, P.E. Nachtigall, and J. Pawloski (1995). Modulation rate transfer functions to low-frequency carriers in three species of cetaceans. Journal of Comparative Physiology. A, Sensory, Neural, and Behavioral Physiology 177(2): 235-245. ISSN: 0340-7594.
NAL Call Number: QP33.J68
Abstract: A temporal modulation rate transfer function (MRTF) is a quantitative description of the ability of a system to follow the temporal envelope of a stimulating waveform. In this study MRTFs were obtained from three cetacean species: the false killer whale Pseudorca crassidens; the beluga whale Delphinapterus leucas; and the bottlenosed dolphin Tursiops truneatus, using auditory-evoked potentials. Steady-state electrophysiological responses were recorded noninvasively from behaving, alert animals using suction cup electrodes placed on the scalp surface. Responses were elicited using continuous two-tone (TT) and sinusoidally amplitude-modulated (SAM) stimuli. MRTFs were obtained for modulation frequencies ranging from 18-4019 Hz using carrier and primary frequencies of 500, 1000, 4000, and 10000 Hz. Scalp potentials followed the low-frequency temporal envelope of the stimulating waveform; this envelope following response (EFR) was the dependent variable in all experiments. MRTFs were generally low-pass in shape with corner frequencies between approximately 1-2 kHz.
Descriptors: marine ecology, ecology, environmental sciences, physiology, sense organs, sensory reception, hearing.
Dubrovskiy, N.A. and L.R. Giro (2003). Modeling of the click-production mechanism in the dolphin. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 59-64.
Online: 0226795993
NAL Call Number: QL737.C5E28 2004
Descriptors: Odontoceti, echolocation, click production physical mechanism modeling.
Erbe, C. (2000). Detection of whale calls in noise: performance comparison between a beluga whale, human listeners, and a neural network. Journal of the Acoustical Society of America 108(1): 297-303. ISSN: 0001-4966.
Abstract: This article examines the masking by anthropogenic noise of beluga whale calls. Results from human masking experiments and a software backpropagation neural network are compared to the performance of a trained beluga whale. The goal was to find an accurate, reliable, and fast model to replace lengthy and expensive animal experiments. A beluga call was masked by three types of noise, an icebreaker's bubbler system and propeller noise, and ambient arctic ice-cracking noise. Both the human experiment and the neural network successfully modeled the beluga data in the sense that they classified the noises in the same order from strongest to weakest masking as the whale and with similar call-detection thresholds. The neural network slightly outperformed the humans. Both models were then used to predict the masking of a fourth type of noise, Gaussian white noise. Their prediction ability was judged by returning to the aquarium to measure masked-hearing thresholds of a beluga in white noise. Both models and the whale identified bubbler noise as the strongest masker, followed by ramming, then white noise. Natural ice-cracking noise masked the least. However, the humans and the neural network slightly overpredicted the amount of masking for white noise. This is neglecting individual variation in belugas, because only one animal could be trained. Comparing the human model to the neural network model, the latter has the advantage of objectivity, reproducibility of results, and efficiency, particularly if the interference of a large number of signals and noise is to be examined.
Descriptors: neural networks computer, sound localization, vocalization, animal physiology, behavior, animal physiology, noise, whales.
Esser, K.H. and A. Eiermann (2003). Processing of frequency-modulated sounds in the Carollia auditory and frontal cortex. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 190-195. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Carollia perspicillata, brain, auditory and frontal cortex, echolocation signals processing, echolocation.
Fahner, M., J. Thomas, K. Ramirez and J. Boehm (2003). Acoustic properties of echolocation signals by captive Pacific white-sided dolphins (Lagenorhynchus obliquidens). In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 53-59. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Lagenorhynchus obliquidens, echolocation, signals acoustic properties.
Filatova, O.A., A.M. Burdin, E. Hoyt, and H. Sato (2004). A catalogue of discrete calls of resident killer whales (Orcinus orca) from the Avacha Gulf of Kamchatka Peninsula. Zoologicheskii Zhurnal 83(9): 1169-1180. ISSN: 0044-5134.
NAL Call Number: 410 R92
Abstract: A classification of killer whale calls recorded in the Avacha Gulf (Kamchatka Peninsula) in 1999-2003 is given. Most of the calls falls into discrete structural categories with higher or lower variability that allows to discern from one to seven subtypes. However, in the repertoire of whales, some highly aberrant variants of discrete call types and highly variable calls also occur. They might not be classified into some definite categories. Such differences in the sound structure appear to be the results of their variable functions.
Descriptors: Orcinus orca, behavioral variation, learning, acoustic signals, discrete calls, repertoire and individual variation, north Pacific, Russia, Kamchatka, Avacha Gulf, discrete calls repertoire and individual variation, role of young learning.
Finneran, J.J. (2003). Whole-lung resonance in a bottlenose dolphin (Tursiops truncatus) and white whale (Delphinapterus leucas). Journal of the Acoustical Society of America 114(1): 529-35. ISSN: 0001-4966.
Abstract: An acoustic backscatter technique was used to estimate in vivo whole-lung resonant frequencies in a bottlenose dolphin (Tursiops truncatus) and white whale (Delphinapterus leucas). Subjects were trained to submerge and position themselves near an underwater sound projector and a receiving hydrophone. Acoustic pressure measurements were made near the thorax while the subject was insonified with pure tones at frequencies from 16 to 100 Hz. Whole-lung resonant frequencies were estimated by comparing pressures measured near the subject's thorax to those measured from the same location without the subject present. Experimentally measured resonant frequencies for the white whale and dolphin lungs were 30 and 36 Hz, respectively. These values were significantly higher than those predicted using a free-spherical air bubble model. Experimentally measured damping ratios and quality factors at resonance were 0.20 and 2.5, respectively, for the white whale, and 0.16 and 3.1, respectively, for the dolphin.
Descriptors: acoustic stimulation, dolphins physiology, lung physiology, whales physiology, lung injuries, lung radiography, noise adverse effects, risk assessment, scattering, radiation, sound spectrography, tomography, x ray computed.
Finneran, J.J., C.E. Schlundt, D.A. Carder, and S.H. Ridgway (2002). Auditory filter shapes for the bottlenose dolphin (Tursiops truncatus) and the white whale (Delphinapterus leucas) derived with notched noise. Journal of the Acoustical Society of America 112(1): 322-8. ISSN: 0001-4966.
Abstract: Auditory filter shapes were estimated in two bottlenose dolphins (Tursiops truncatus) and one white whale (Delphinapterus leucas) using a behavioral response paradigm and notched noise. Masked thresholds were measured at 20 and 30 kHz. Masking noise was centered at the test tone and had a bandwidth of 1.5 times the tone frequency. Half-notch width to center frequency ratios were 0, 0.125, 0.25, 0.375, and 0.5. Noise spectral density levels were 90 and 105 dB re: 1 microPa2/Hz. Filter shapes were approximated using a roex(p,r) function; the parameters p and r were found by fitting the integral of the roex(p,r) function to the measured threshold data. Mean equivalent rectangular bandwidths (ERBs) calculated from the filter shapes were 11.8 and 17.1% of the center frequency at 20 and 30 kHz, respectively, for the dolphins and 9.1 and 15.3% of the center frequency at 20 and 30 kHz, respectively, for the white whale. Filter shapes were broader at 30 kHz and 105 dB re: 1 microPa2/Hz masking noise. The results are in general agreement with previous estimates of ERBs in Tursiops obtained with a behavioral response paradigm.
Descriptors: auditory perception, noise, auditory threshold physiology, dolphins, hearing physiology, models, biological, perceptual masking, whales.
Finneran, J.J. (2003). Whole-lung resonance in a bottlenose dolphin (Tursiops truncatus) and white whale (Delphinapterus leucas). Journal of the Acoustical Society of America 114(1): 529-535. ISSN: 0001-4966.
Descriptors: mathematical biology, computational biology, models and simulations, respiratory system, respiration, sense organs, sensory reception, acoustic backscatter technique, acoustic pressure measurement, damping ratios, free spherical air bubble model, pure tones, quality factors, resonant frequency, tone frequency, white whale, bottlenose dolphin.
Frantzis, A., J.C. Goold, E.K. Skarsoulis, M.I. Taroudakis, and V. Kandia (2002). Clicks from Cuvier's beaked whales, Ziphius cavirostris. Journal of the Acoustical Society of America 112(1): 34-7. ISSN: 0001-4966.
Descriptors: animal communication, acoustics, echolocation physiology, whales physiology.
Fripp, D. (2005). Bubblestream whistles are not representative of a bottlenose dolphin's vocal repertoire. Marine Mammal Science 21(1): 29-44. ISSN: 0824-0469.
NAL Call Number: QL713.2.M372
Abstract: Whistling bottlenose dolphins sometimes identify themselves with a concurrent bubblestream, and some researchers use these bubblestream whistles as their sole whistle sample. However, bubblestream whistles are not known to be representative of the entire repertoire. Bubblestreams and whistles were recorded from three captive female dolphins and their newborn calves. Bubblestreams were rare (0.13/min), with calves producing ten times as many as adults. Overall, 79% of bubblestreams were associated with whistles, but only 196 of whistles were associated with bubblestreams. Bubblestream whistles were not independent: 49% occurred within I sec of another bubblestream, and 72% of these had the same contour as other bubblestream whistles in the bout. Bubblestream use was context-dependent: adults were more likely to bubblestream when caring for a calf (P 0.001), and calves were more likely to bubblestream when other calves were present (P 0.001). Bubblestreams were not associated with all whistle types. Bubblestream whistles were not evenly distributed across the clusters of a hierarchical cluster analysis of contour parameters using 300 randomly selected non-bubblestream whistles and 92 independent bubblestream whistles (10 clusters, P = 0.003). In conclusion, bubblestreams are rare visual cues that dolphins produce in association with certain whistles in certain contexts and are not representative of the dolphin's repertoire.
Descriptors: Tursiops truncatus, acoustic signals, vocal repertoire, bubblestream whistle correlations.
Fripp, D., C. Owen, E. Quintana Rizzo, A. Shapiro, K. Buckstaff, K. Jankowski, R. Wells, and P. Tyack (2005). Bottlenose dolphin (Tursiops truncatus) calves appear to model their signature whistles on the signature whistles of community members. Animal Cognition 8(1): 17-26. ISSN: 1435-9448.
Abstract: Bottlenose dolphins are unusual among non-human mammals in their ability to learn new sounds. This study investigates the importance of vocal teaming in the development of dolphin signature whistles and the influence of social interactions on that process. We used focal animal behavioral follows to observe six calves in Sarasota Bay, Fla., recording their social associations during their first summer. and their signature whistles during their second. The signature whistles of five calves were determined. Using dynamic time warping (DTW) of frequency contours, the calves' signature whistles were compared to the signature whistles of several sets of dolphins: their own associates, the other calves' associates, Tampa Bay dolphins, and captive dolphins. Whistles were considered similar if their DTW similarity score was greater than those of 95% of the whistle comparisons. Association was defined primarily in terms of time within 50 in of the mother/calf pair. On average, there were six dolphins with signature whistles similar to the signature whistles of each of the calves. These were significantly more likely to be Sarasota Bay resident dolphins than non-Sarasota dolphins, and (though not significantly) more likely to be dolphins that were within 50 in of the mother and calf less than 5% of the time. These results suggest that calves may model their signature whistles on the signature whistles of members of their community, possibly community members with whom they associate only rarely.
Descriptors: Tursiops truncatus, learning, acoustic signals, social behavior, Gulf of Mexico, USA, Florida, Sarasota Bay, signature whistles, learning in young, influence of social interactions.
Fristrup, K.M., L.T. Hatch, and C.W. Clark (2003). Variation in humpback whale (Megaptera novaeangliae) song length in relation to low-frequency sound broadcasts. Journal of the Acoustical Society of America 113(6): 3411-24. ISSN: 0001-4966.
Abstract: Humpback whale song lengths were measured from recordings made off the west coast of the island of Hawai'i in March 1998 in relation to acoustic broadcasts ("pings") from the U.S. Navy SURTASS Low Frequency Active sonar system. Generalized additive models were used to investigate the relationships between song length and time of year, time of day, and broadcast factors. There were significant seasonal and diurnal effects. The seasonal factor was associated with changes in the density of whales sighted near shore. The diurnal factor was associated with changes in surface social activity. Songs that ended within a few minutes of the most recent ping tended to be longer than songs sung during control periods. Many songs that were overlapped by pings, and songs that ended several minutes after the most recent ping, did not differ from songs sung in control periods. The longest songs were sung between 1 and 2 h after the last ping. Humpbacks responded to louder broadcasts with longer songs. The fraction of variation in song length that could be attributed to broadcast factors was low. Much of the variation in humpback song length remains unexplained.
Descriptors: animal communication, circadian rhythm, seasons, social behavior, social environment, sound spectrography classification, vocalization, animal classification, whales psychology, Hawaii, regression analysis.
Fuzessery, Z.M., A.S. Feng and A. Supin (2003). Central auditory processing of temporal information in bats and dolphins. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 115-123. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Odontoceti, micro-Chiroptera, brain, central auditory system, spectrotemporal information processing, echolocation.
Gannon, D.P., N.B. Barros, D.P. Nowacek, A.J. Read, D.M. Waples, and R.S. Wells (2005). Prey detection by bottlenose dolphins, Tursiops truncatus: an experimental test of the passive listening hypothesis. Animal Behaviour 69: 709-720. ISSN: 0003-3472.
NAL Call Number: 410 B77
Descriptors: behavior, sense organs, sensory reception, evolution and adaptation, predation, foraging, echolocation, prey detection, passive listening hypothesis, fish sound.
Gardner, S.C. and U. Varanasi (2003). Isovaleric acid accumulation in odontocete melon during development. Naturwissenschaften 90(11): 528-531. ISSN: 0028-1042.
NAL Call Number: 474 N213
Descriptors: Tursiops truncatus, Phocoena phocoena, spermaceti organ, melon, isovaleric acid accumulation during development, lipids, isovaleric acid, development.
Glezer, I.L., P. Hof, P.J. Morgane, A. Fridman, T. Isakova, D. Joseph, A. Nair, P. Parhar, A. Thengampallil, S. Thomas, R. Venugopal and G.H. Jung (2003). Chemical neuroanatomy of the inferior colliculus in brains of echolocating and nonecholocating mammals: immunocytochemical study. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 161-172. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: mammalia, proteins, calbindin, calretinin and parvalbumin, inferior colliculus chemical neuroanatomy in echolocating and non echolocating taxa, brain, inferior colliculus, chemical neuroanatomy in echolocating and non echolocating taxa, echolocation, inferior colliculus chemical neuroanatomy relationship.
Goodson, A.D., O. Farooq, and S. Datta (2001). Phase and amplitude changes in echolocation signals from the harbour porpoise. Proceedings of the Institute of Acoustics 23(4): 133-140. ISSN: 0309-8117.
Descriptors: Phocoena phocoena, echolocation, signal components.
Goodson, A.D., J.A. Flint and T.W. Cranford (2003). The harbor porpoise (Phocoena phocoena) - modeling the sonar transmission mechanism. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 64-72. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: pisces, mammalian predators, Phocoena phocoena, prey detection and predator sonar transmission constraints.
Goold, J.C. and S.E. Jones (1995). Time and frequency domain characteristics of sperm whale clicks. Journal of the Acoustical Society of America 98(3): 1279-91. ISSN: 0001-4966.
Abstract: Regular clicks from diving sperm whales, both large bull males and smaller females, were recorded in deep oceanic water off the Azores and subsequently sampled to computer disks for digital analysis. A total of 8540 clicks were marked and analyzed. Simple temporal analysis of the interclick intervals during feeding dives revealed mean click rates for male sperm whales of 1.1713 s-1 and 1.9455 s-1 for females. Fourier analysis showed distinctive peaks in the spectra of bull male sperm whales at 400 Hz and 2 kHz which were stable over extended periods of up to 20 mins. The clicks contained higher frequency components with energy ranging up to at least 12 kHz but not concentrated at any sharply defined frequency. The clicks of smaller female sperm whales showed similar spectral peaks, shifted to 1.2 and 3 kHz, respectively, but these peaks were less pronounced than those in the male click spectra and less stable with time. Higher frequencies were also present up to at least 15 kHz. The previously reported multiple pulse structure of sperm whale clicks is confirmed, but digital filtering reveals this structure to be frequency dependent. Analysis using the short-time Fourier transform confirms the complex time-frequency structure of individual clicks. The frequencies at which the multiples emerge in male and female clicks supports the idea of air cavities in the sperm whale head acting as sound reflectors, although the magnitude of the second pulse at high frequencies suggests some form of off axis distortion. It is also possible that air cavity resonance in the head of the sperm whale may act to reinforce the high-frequency components of the click, and that such components may have superior range and resolution performance in terms of echolocation.
Descriptors: animal communication, whales physiology, fourier analysis, time factors, whales anatomy and histology.
Gordon, J. and P.L. Tyack (2001). Acoustic techniques for studying cetaceans. In: P.G.H. Evans and J.A. Raga (Editors), Marine Mammals: Biology and Conservation, Kluwer Academic/Plenum Publishers: New York, p. 293-324. ISBN: 0306465736.
NAL Call Number: QL713.2.M354 2001
Descriptors: Cetacea, literature review, behavioral techniques, biometrical techniques, body length determination techniques, ecological techniques, acoustic techniques, review.
Gordon, J. and P.L. Tyack (2001). Sound and Cetaceans. In: P.G.H. Evans and J.A. Raga (Editors), Marine Mammals: Biology and Conservation, Kluwer Academic/Plenum Publishers: New York, p. 139-196. ISBN: 0306465736.
NAL Call Number: QL713.2.M354 2001
Descriptors: Cetacea, literature review, sound reception, echolocation, acoustic signals, review.
Harley, H.E., E.A. Putman, and H.L. Roitblat (2003). Bottlenose dolphins perceive object features through echolocation. Nature (London) 424(6949): 667-9. ISSN: 1476-4687.
NAL Call Number: 472 N21
Abstract: How organisms (including people) recognize distant objects is a fundamental question. The correspondence between object characteristics (distal stimuli), like visual shape, and sensory characteristics (proximal stimuli), like retinal projection, is ambiguous. The view that sensory systems are 'designed' to 'pick up' ecologically useful information is vague about how such mechanisms might work. In echolocating dolphins, which are studied as models for object recognition sonar systems, the correspondence between echo characteristics and object characteristics is less clear. Many cognitive scientists assume that object characteristics are extracted from proximal stimuli, but evidence for this remains ambiguous. For example, a dolphin may store 'sound templates' in its brain and identify whole objects by listening for a particular sound. Alternatively, a dolphin's brain may contain algorithms, derived through natural endowments or experience or both, which allow it to identify object characteristics based on sounds. The standard method used to address this question in many species is indirect and has led to equivocal results with dolphins. Here we outline an appropriate method and test it to show that dolphins extract object characteristics directly from echoes.
Descriptors: dolphins physiology, echolocation physiology, perception physiology, environment, models, biological, physical stimulation.
Harley, H.E. (2003). Identity versus conditional cross-modal matching by the bottlenose dolphin. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 283-287. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Tursiops truncatus, echolocation, object recognition mechanisms, identity vs conditional cross modal matching, learning.
Helweg, D.A., P.W. Moore, L.A. Dankiewicz, J.M. Zafran, and R.L. Brill (2003). Discrimination of complex synthetic echoes by an echolocating bottlenose dolphin. Journal of the Acoustical Society of America 113(2): 1138-44. ISSN: 0001-4966.
Abstract: Bottlenose dolphins (Tursiops truncatus) detect and discriminate underwater objects by interrogating the environment with their native echolocation capabilities. Study of dolphins' ability to detect complex (multihighlight) signals in noise suggest echolocation object detection using an approximate 265-micros energy integration time window sensitive to the echo region of highest energy or containing the highlight with highest energy. Backscatter from many real objects contains multiple highlights, distributed over multiple integration windows and with varying amplitude relationships. This study used synthetic echoes with complex highlight structures to test whether high-amplitude initial highlights would interfere with discrimination of low-amplitude trailing highlights. A dolphin was trained to discriminate two-highlight synthetic echoes using differences in the center frequencies of the second highlights. The energy ratio (delta dB) and the timing relationship (delta T) between the first and second highlights were manipulated. An iso-sensitivity function was derived using a factorial design testing delta dB at -10, -15, -20, and -25 dB and delta T at 10, 20, 40, and 80 micros. The results suggest that the animal processed multiple echo highlights as separable analyzable features in the discrimination task, perhaps perceived through differences in spectral rippling across the duration of the echoes.
Descriptors: attention physiology, dolphins physiology, echolocation physiology, pitch discrimination physiology, acoustic stimulation, auditory threshold physiology, psychoacoustics, sound spectrography.
Helweg, D.A., H.L. Roiblat, P.E. Nachtigall, and M.J. Hautus (1996). Recognition of aspect-dependent three-dimensional objects by an echolocating Atlantic bottlenose dolphin. Journal of Experimental Psychology. Animal Behavior Processes 22(1): 19-31. ISSN: 0097-7403.
NAL Call Number: QL750.J682
Descriptors: Tursiops truncatus, acoustic tracking, orientation, learning ability.
Hemila, S., S. Nummela, and T. Reuter (2001). Modeling whale audiograms: effects of bone mass on high-frequency hearing. Hearing Research 151(1-2): 221-226. ISSN: 0378-5955.
Abstract: In a previous paper (Hemila et al., Hear. Res. 133 (1999) 82-97) we have presented a mechanical model, based on species-specific anatomical data, for the toothed whale middle ear. For five odontocete species of six we found that the model quite well predicted published behavioral audiograms. Here we report that new published data indicate that the audiogram of the sixth and deviating species, the killer whale Orcinus orca, was from a specimen with deficient high-frequency hearing. A new published killer whale audiogram is similar to other odontocete audiograms and does fit our four-bone model. With certain general conditions, a model with isometric (middle) ears results in uniform audiograms for different species, when presented in a log-log plot; with larger ears the audiogram curves are just moved towards lower frequencies. The audiograms coincide in case all frequencies are scaled by a factor 1/m3, where m is the mass of the ear ossicles. Odontocete ears are isometric enough to show that the corresponding audiograms are indeed similar after such mass scaling. Specifically, this scaling factor can be used to predict the high-frequency hearing limits of all odontocete species. Our anatomical data and models support the notion that ossicular mass is a crucial factor limiting high-frequency hearing in both terrestrial mammals and toothed whales.
Descriptors: hearing physiology, models, biological, whales anatomy and histology, whales physiology, bone and bones anatomy and histology, middle ear anatomy and histology, middle ear physiology, organ size, species specificity.
Herzing, D.L. (2003). Social and nonsocial uses of echolocation in free-ranging Stenella frontalis and Tursiops truncatus. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 404-410. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Stenella frontalis, Tursiops truncatus, foraging, defensive behavior, vigilance, social behavior, Caribbean Sea, Bahamas, social and non social uses of echolocation.
Herzing, D.L. (2000). Acoustics and social behavior of wild dolphins: implications for a sound society. In: W.W.L. Au, A.N. Popper and R.R. Fay (Editors), Hearing by Whales and Dolphins, Springer Handbook of Auditory Research, p. 225-272. ISBN: 0387949062.
NAL Call Number: QL737.C432H43 2000
Descriptors: Delphinidae, literature review, acoustic signals, role in social behavior, review, social behavior.
Herzing, D.L. and M.E. dos Santos (2003). Functional aspects of echolocation in dolphins. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 386-393. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Odontoceti, echolocation, functional aspects review, foraging, social behavior.
Higashi, N., A. Takemura, J. Kubota, and S. Uchida (1992). Calls of the short-finned pilot whale, Globicephala macrorhynchus, in the coastal waters of Okinawa, southern Japan. Bulletin of the Faculty of Fisheries Nagasaki University (72): 5-10. ISSN: 0547-1427.
Descriptors: whales, sound, communication between animals, coastal waters, Cetacea, mammals, marine areas, radiation.
Language of Text: English summary.
Himei, S., H. Kuroda, A. Takemura, and T. Koido (2000). On the classification of whistles of bottle-nosed dolphins. Bulletin of the Faculty of Fisheries Nagasaki University (81): 77-79. ISSN: 0547-1427.
Descriptors: dolphins, sound, communication between animals, imagery, acoustic properties, Cetacea, chemicophysical properties, mammals, methods, radiation.
Language of Text: English summary.
Hoelzel, A.R. and R.W. Osborne (1986). Killer whale call characteristics: implications for cooperative foraging strategies. Zoo Biology Monographs 1: 373-403.
Descriptors: Orcinus orca, foraging, cooperative strategies, vocalizations, implications for foraging, social behavior, cooperative foraging, implications of calls, Washington, north Pacific, call characteristics, implications for cooperative foraging strategies.
Houser, D., S.W. Martin, E.J. Bauer, M. Phillips, T. Herrin, M. Cross, A. Vidal, and P.W. Moore (2005). Echolocation characteristics of free-swimming bottlenose dolphins during object detection and identification. Journal of the Acoustical Society of America 117(4, Pt. 1): 2308-2317. ISSN: 0001-4966.
Abstract: A biosonar measurement tool (BMT) was created to investigate dolphin echolocation search strategies by recording echolocation clicks, returning echoes, and three-dimensional angular motion, velocity, and depth of free-swimming dolphins performing open-water target detections. Trial start and stop times, locations determined from a differential global positioning system (DGPS), and BMT motion and acoustic data were used to produce spatial and acoustic representations of the searches. Two dolphins (LUT, FLP) searched for targets lying on the seafloor of a bay environment while carrying the BMT. LUT searched rapidly (< 10 s), produced few clicks, and varied click-peak frequency (20-120 kHz); FLP searched relatively slowly (tens of seconds) and produced many hundreds of clicks with stereotypical frequency-dependent energy distributions dominating from 30-60 kHz. Dolphins amplified target echo returns by either increasing the click source level or reducing distance to the target but without reducing source level. The distribution of echolocation click-peak frequencies suggested a bias in the dominant frequency components of clicks, possibly due to mechanical constraints of the click generator. Prior training and hearing loss accommodation potentially explain differences in the search strategies of the two dolphins.
Descriptors: biosonar, echolocation, clicks, depth, frequency, object detection, identification, search strategies, dolphins.
Houser, D.S., J. Finneran, D. Carder, W. Van Bonn, C. Smith, C. Hoh, R. Mattrey, and S. Ridgway (2004). Structural and functional imaging of bottlenose dolphin (Tursiops truncatus) cranial anatomy. Journal of Experimental Biology 207(21): 3657-3665. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Abstract: Bottlenose dolphins were submitted to structural (CT) and functional (SPECT/PET) scans to investigate their in vivo anatomy and physiology with respect to structures important to hearing and echolocation. The spatial arrangement of the nasal passage and sinus air spaces to the auditory bullae and phonic lips was studied in two dolphins via CT. Air volume of the sinuses and nasal passages ranged from 267.4 to 380.9 ml. Relationships of air spaces to the auditory bullae and phonic lips support previous hypotheses that air protects the ears from echolocation clicks generated by the dolphin and contributes to dolphin hearing capabilities (e.g. minimum angular resolution, inter-aural intensity differences). Lung air may replenish reductions in sinus and nasal passage air volume via the palatopharyngeal sphincter, thus permitting the echolocation mechanism to operate at depth. To determine the relative extent of regional blood flow within the head of the dolphin, two dolphins were scanned with SPECT after an intravenous dose of 1850 MBq 99mTc-bicisate. A single dolphin received 740 MBq of 18F-2-fluoro-2-deoxyglucose (FDG) to identify the relative metabolic activity of head tissues. Substantial blood flow was noted across the dorsoanterior curvature of the melon and within the posterior region of the lower jaw fats. Metabolism of these tissues relative to others within the head was nominal. It is suggested that blood flow in these fat bodies serves to thermoregulate lipid density of the melon and jaw canal. Sound velocity is inversely related to the temperature of acoustic lipids (decreasing lipid density), and changes in lipid temperature are likely to impact the wave guide properties of the sound projection and reception pathways. Thermoregulation of lipid density may maintain sound velocity gradients of the acoustic lipid complexes, particularly in the outer shell of the melon, which otherwise might vary in response to changing environmental temperatures.
Descriptors: bottlenose dolphins, CT, SPECT, PT, scans, anatomy, physiology, hearing, echolocation, melon, sinuse air spaces, auditory bullae.
Ishii, K. (1990). Firmware development system for dolphin's clicks waveform reproduction. Bulletin of National Research Institute of Fisheries Engineering (11): 251-280. ISSN: 0388-9718.
NAL Call Number: SH301.S852
Abstract: The author has researched the dolphin's behavior control technique to prevent them from being caught in drift nets. An acoustic study on Dall's porpoises in the Sea of Okhotsk off Hokkaido in 1985 is reported as follows: When porpoises were floating with ease around the vessel, and the sound waves were given off, they started to jump up and escaped in a direction away from transmitter. The signal source was synthesized using supersonic sinusoidal waves. As a result of this sound projection experiment, the author is of the opinion that clicks transmitted by dolphins themselves are more significant as a signal source of the threading device in respect to ecology. Then, the author designed a biosonar simulator and developed software, calling at the firmware development system for clicks waveform reproduction. This software has a consistent routine from drawing of a parameter and data by modeling program into IC memory chip. Wave parameters are evaluated from graphs made by the clicks acquisition system. The modeling divides the clicks between burst and waiting periods. The IC memory written clicks wave data is loaded into the biosonar simulator as the signal source of the projection supersonic.
Descriptors: dolphins, sound, vibration, computer software, behavior, acoustic properties, Cetacea, chemicophysical properties, mammals, radiations.
Language of Text: English summary.
Ishii, K. (1989). Acquisition system of biosonar, the clicks used by dolphins. Bulletin of National Research Institute of Fisheries Engineering (10): 189-214. ISSN: 0388-9718.
NAL Call Number: SH301.S852
Descriptors: dolphins, sound, data collection, acoustic properties, electrical engineering, Cetacea, chemicophysical properties, engineering, information science, mammals, radiations.
Language of Text: English summary.
Ishii, K., T. Akamatsu, and Y. Hatakeyama (1992). Design of the biosonar simulator for dolphin's clicks waveform reproduction. Bulletin of National Research Institute of Fisheries Engineering (13): 95-128. ISSN: 0388-9718.
NAL Call Number: SH301.S852
Abstract: Clicks of Dall's porpoises are pulse train of burst signals with an ultrasonic carrier frequency. The authors have designed the biosonar simulator for dolphin's clicks waveform reproduction under water. The total reproduction system consists of a clicks signal acquisition block, a waveform analysis block, a memory unit, a simulator of clicks signal and a transmitter of an ultrasonic wave under water. In the sea, data memorized in an EPROM are read out sequentially by a fast clock and converted to analog output signals. Then an ultrasonic power amplifier reproduces these signals through a transmitter against dolphins under water. Clicks signal replaying block is called Biosonar Simulator (BSS), which simulates the clicks of dolphin. The details of BSS are described in this paper. A unit waveform is defined, which is divided into a burst period and a waiting period. Clicks is a train of a unit waveform, where digital data are sequentially read out from EPROM of waveform data dependent on parameters. The basic functions of BSS are as follows. (1) Reading clock: 100 ns - 25.4 mus. (2) Number of reading clock: 34 - 1024 times. (3) Counter clock in a waiting period: 100 ns - 25.4 mus. (4) Number of count clock: 0 - 16777215 times. (5) Number of burst/waiting repetition cycle: 1 - 128 times. (6) Transmission level adjustment by a programmable attenuator: 0 - 86.5dB. These basic functions enable a biosonar simulator to replay clicks of Dall's porpoise precisely.
Descriptors: Delphinus, behavior, equipment, reproduction, animal sciences, Cetacea, dolphins, mammals, physiological functions.
Language of Text: English summary.
Ishii, K., T. Akamatsu, Y. Hatakeyama, T. Kojima, T. Shimamura, and H. Soeda (1993). Design of the buoy system simulating the biosonar for dolphin's clicks waveform reproduction. Bulletin of National Research Institute of Fisheries Engineering (14): 201-214. ISSN: 0388-9718.
NAL Call Number: SH301.S852
Abstract: The authors have designed the sound generator in a buoy for the purpose of preventing dolphins from getting entangled in gill nets. The sound sources are the clicks transmitted by Dall's porpoise in an emergency and is stored into the built-in IC in the buoy system. In the sea, the wave data memorized in an EPROM are readout sequentially as ON/OFF trigger signals to the power amplifier. Then an ultrasonic power amplifier reproduces these signals through a transmitter against dolphins under water.
Descriptors: dolphins, sound, acoustic properties, scares, gillnets, ultrasonics, equipment, design, Cetacea, chemicophysical properties, equipment, fishing gear, fishing nets, mammals, pest control equipment, pest control methods, radiations, repellents, sound.
Language of Text: English summary.
Ishii, K. and Y. Hatakeyama (1987). Bottlenose dolphin's [Tursiopus gilli] whistles recorded acquired with filtering. Bulletin of National Research Institute of Fisheries Engineering (8): 141-168. ISSN: 0388-9718.
NAL Call Number: SH301.S852
Descriptors: Tursiops, sound, acoustic properties, Cetacea, chemicophysical properties, mammals, physics, vertebrates.
Language of Text: English summary.
Ishii, K. and Y. Hatakeyama (1987). The design of marine transponder with GP-IB [devices for driving away dolphins]. Bulletin of National Research Institute of Fisheries Engineering (8): 113-139. ISSN: 0388-9718.
NAL Call Number: SH301.S852
Descriptors: dolphins, noxious mammals, pest control, ultrasonics, noise, electrical installations, animals, aquatic animals, aquatic mammals, aquatic organisms, Cetacea, control, electrification, equipment, injurious factors, ISSCAAP group b 63, ISSCAAP groups of species, mammals, noise, noxious animals, pests, physics, pollutants, sound, vertebrates.
Language of Text: English summary.
Janik, V.M. (2000). Food-related bray calls in wild bottlenose dolphins (Tursiops truncatus). Proceedings of the Royal Society of London. Series B. Biological Sciences 267(1446): 923-7. ISSN: 0962-8452.
Abstract: Because cetaceans are difficult to study in the wild, little is known about how they use their sounds in their natural environment. Only the recent development of passive acoustic localization systems has enabled observations of the communication behaviour of individuals for correlation with their surface behaviour. Using such a system, I show that bottlenose dolphins in the Moray Firth, Scotland, produce low-frequency bray calls which are clearly correlated with feeding on salmonids. The production of these calls is followed by fast approaches by conspecifics in the area. In animals which use sound as a foraging tool, it is difficult to distinguish between food calls which have evolved because of their role in attracting conspecifics, and food manipulation or searching calls which may attract conspecifics as a by-product. However, the low-frequency structure of the bottlenose dolphin bray suggests that it evolved because of a role in manipulating prey rather than in attracting conspecifics. This conclusion suggests that dolphins exploit the perceptual systems of their prey to facilitate capture.
Descriptors: dolphins physiology, feeding behavior, Salmonidae, Scotland, vocalization, animal.
Jaquet, N., S. Dawson, and L. Douglas (2001). Vocal behavior of male sperm whales: why do they click? Journal of the Acoustical Society of America 109(5, Pt. 1): 2254-9. ISSN: 0001-4966.
Abstract: Off Kaikoura, New Zealand, we recorded individually identified male sperm whales (Physeter macrocephalus) for entire dive cycles in order to investigate vocal behavior of individual whales and to examine possible functions of sperm whale clicks. In our study, sperm whales were almost always silent at the surface. They consistently started clicking within 25 s after fluking-up and diving. During the first 10 s of clicking, interclick intervals were significantly correlated with water depths at the location of fluke-up. The first "creak" was produced on average 7.5 min into a dive. Interclick intervals usually decreased substantially before clicks turned into "creaks." The highest click rate recorded in this study was 90.9 click/s, and clicks-within-creaks were much shorter than "usual clicks" (mean of 3.6 ms versus 17 to 30 ms). The number of creaks per minute of dive and the length of a dive were significantly correlated. On average, sperm whales were silent for the last 3.6 min before surfacing. Short sequences of "surface clicks" (3 to 8 metallic clicks with mean interclick interval of 5.5 s) were often produced at the end of a dive (in 57% of the dives), but their function remains puzzling. The results of this study suggest that usual clicks and creaks are both used for echolocation purposes, the former to gather information about acoustically reflective features and the latter to detect prey.
Descriptors: vocalization, animal physiology, whales physiology, echolocation physiology.
Johnson, M., P.T. Madsen, W.M.X. Zimmer, N. Aguilar de Soto, and P.L. Tyack (2004). Beaked whales echolocate on prey. Proceedings of the Royal Society of London. Series B. Biological Sciences 271 (Suppl. 6): S383-S386. ISSN: 0962-8452.
Abstract: Beaked whales (Cetacea: Ziphiidea) of the genera Ziphius and Mesoplodon are so difficult to study that they are mostly known from strandings. How these elusive toothed whales use and react to sound is of concern because they mass strand during naval sonar exercises. A new non-invasive acoustic recording tag was attached to four beaked whales (two Mesoplodon densirostris and two Ziphius cavirostris) and recorded high-frequency clicks during deep dives. The tagged whales only clicked at depths below 200 m, down to a maximum depth of 1267 m. Both species produced a large number of short, directional, ultrasonic clicks with no significant energy below 20 kHz. The tags recorded echoes from prey items; to our knowledge, a first for any animal echolocating in the wild. As far as we are aware, these echoes provide the first direct evidence on how free-ranging toothed whales use echolocation in foraging. The strength of these echoes suggests that the source level of Mesoplodon clicks is in the range of 200-220 dB re 1 [mu]Pa at 1 m. This paper presents conclusive data on the normal vocalizations of these beaked whale species, which may enable acoustic monitoring to mitigate exposure to sounds intense enough to harm them.
Descriptors: Mesoplodon densirostris, echolocation, depth range, first direct evidence of use in foraging, foraging, depth, North Atlantic, Canary Islands, foraging echolocation, depth range and first direct evidence of use.
Jonker, F.C. and S.M. Ferreira (2004). Can echolocation devices be used to define harbour use by Maui's dolphins? DOC Science Internal Series 161: 1-21. ISSN: 1175-6519.
Abstract: A pilot study was undertaken from 1 April to 30 June 2003 to investigate the distributional movement patterns of the MauiÆs dolphin (Cephalorhynchus hectori maui) within the Manukau Harbour region, New Zealand. Porpoise detection devices (PODs), which are self-contained submersible computers and hydrophone loggers that recognise and log echolocation ultrasound clicks of dolphins, were used. æAcoustic fencesÆ could be established across the width of the harbour entrance, using PODs to analyse time-specific data on direction of movement and time spent inside the harbour by MauiÆs dolphins. The pilot study was focused on calibrating the PODs and determining the feasibility of using them. Controlled POD tests were on recorded HectorÆs dolphin sounds over two days and again in different waterbodies within the Manukau Harbour. POD tests for dolphins actually sighted outside of the Manukau Harbour region were also done over a two-day period. Physical constraints important in planned moorings and placement of PODs across the harbour channel mouth were also reviewed. Actual and potential problems with the technique were discussed. Firm conclusions could not be drawn because of the lack of encounters with dolphins during the feasibility trials.
Descriptors: Cephalorhynchus hectori maui, ecological mapping, harbour use analysis, habitat utilization, South Pacific, New Zealand, Manukau harbour region, habitat use analysis, echolocation devices evaluation.
Kanwisher, J. and S. Ridgway (1983). L' ecophysiologie des Cetaces. [Ecophysiology of Cetaceans]. Pour La Science (70): 12-20. ISSN: 0153-4092.
Descriptors: cetaceans, echophysiology.
Karol, R., C. Litchfield, D.K. Caldwell, and M.C. Caldwell (1978). Compositional topography of melon and spermaceti organ lipids in the pygmy sperm whale Kogia breviceps: Implications for echolocation. Marine Biology (Berlin) 47(2): 115-123. ISSN: 0025-3162.
NAL Call Number: QH91.A1M35
Descriptors: topography, melon, spermaceti organ, lipids, pygmy sperm whale, echolocation, composition.
Language of Text: English summary.
Kastelein, R.A., W.W. Au, and D. de Haan (2000). Detection distances of bottom-set gillnets by harbour porpoises (Phocoena phocoena) and bottlenose dolphins (Tursiops truncatus). Marine Environmental Research 49(4): 359-75. ISSN: 0141-1136.
NAL Call Number: QH545.W3M36
Abstract: Many odontocetes die annually in gillnet fisheries. Why they become entangled is not yet clear. Maybe some species detect the nets too late to avoid collision. Therefore, the target strength of 11 types of bottom-set gillnets was measured under 0 and 45 degrees angles of incidence. From these target strengths and from knowledge on the echolocation abilities of two odontocete species (harbour porpoises, bottlenose dolphins), the detection ranges of the nets by these small cetaceans could be estimated. The 90% detection range by echolocating harbour porpoises, approaching the nets at right (perpendicular) angles under low noise level conditions, varied between 3 and 6 m depending on the net type. For bottlenose dolphins, under high noise conditions, the 90% detection range varied between 25 and 55 m. At other angles of approach, the estimated detection ranges are shorter. The study suggests that echolocating bottlenose dolphins can detect nets in time to avoid collision, whereas echolocating harbour porpoises cannot in most cases. Suggestions for future research to reduce small cetacean bycatch by improving the nets' detectability by echolocation are given.
Descriptors: dolphins physiology, echolocation physiology, fisheries instrumentation, porpoises physiology, avoidance learning physiology.
Kastelein, R.A., P. Bunskoek, M. Hagedoorn, W.W. Au, and D. de Haan (2002). Audiogram of a harbor porpoise (Phocoena phocoena) measured with narrow-band frequency-modulated signals. Journal of the Acoustical Society of America 112(1): 334-44. ISSN: 0001-4966.
Abstract: The underwater hearing sensitivity of a two-year-old harbor porpoise was measured in a pool using standard psycho-acoustic techniques. The go/no-go response paradigm and up-down staircase psychometric method were used. Auditory sensitivity was measured by using narrow-band frequency-modulated signals having center frequencies between 250 Hz and 180 kHz. The resulting audiogram was U-shaped with the range of best hearing (defined as 10 dB within maximum sensitivity) from 16 to 140 kHz, with a reduced sensitivity around 64 kHz. Maximum sensitivity (about 33 dB re 1 microPa) occurred between 100 and 140 kHz. This maximum sensitivity range corresponds with the peak frequency of echolocation pulses produced by harbor porpoises (120-130 kHz). Sensitivity falls about 10 dB per octave below 16 kHz and falls off sharply above 140 kHz (260 dB per octave). Compared to a previous audiogram of this species (Andersen, 1970), the present audiogram shows less sensitive hearing between 2 and 8 kHz and more sensitive hearing between 16 and 180 kHz. This harbor porpoise has the highest upper-frequency limit of all odontocetes investigated. The time it took for the porpoise to move its head 22 cm after the signal onset (movement time) was also measured. It increased from about 1 s at 10 dB above threshold, to about 1.5 s at threshold.
Descriptors: auditory perception, hearing physiology, audiometry, echolocation, noise, porpoises, psychoacoustics.
Kastelein, R.A., D. de Haan, N. Vaughan, C. Staal, and N.M. Schooneman (2001). The influence of three acoustic alarms on the behaviour of harbour porpoises (Phocoena phocoena) in a floating pen. Marine Environmental Research 52(4): 351-71. ISSN: 0141-1136.
NAL Call Number: QH545.W3M36
Abstract: Harbour porpoise bycatch may be reduced by deterring porpoises from nets acoustically. In this study, two harbour porpoises were subjected to three acoustic alarms. The effect of each alarm was judged by comparing the animals' position and respiration rate during a test period with that during a baseline period. The XP-10 alarm produced 0.3 s tonal signals randomly selected from a set of 16 with fundamental frequencies between 9 and 15 kHz, with a constant pulse interval of 4.8 s (duty cycle 6%). The 2MP alarm produced 0.3 s tonal signals randomly selected from a set of 16 with similar fundamental frequencies but with random pulse intervals of between 2 and 5 s (duty cycle 8%). The frequency spectra and source levels of the 2MP and XP-10 alarms varied depending on the signal selected. The HS20-80 alarm produced a constant, but asymmetrical frequency modulated sinewave between 20 and 80 kHz with total pulse duration of 0.3 s. with random pulse intervals of between 2 and 5 s (duty cycle 4.6%). The porpoises reacted to all three alarms by swimming away from them and by increasing their respiration rate. The XP-10, which on average had the highest source level, had the strongest effect.
Descriptors: acoustics, avoidance learning, porpoises psychology, respiration.
Kastelein, R.A., M. Hagedoorn, W.W. Au, and D. de Haan (2003). Audiogram of a striped dolphin (Stenella coeruleoalba). Journal of the Acoustical Society of America 113(2): 1130-7. ISSN: 0001-4966.
Abstract: The underwater hearing sensitivity of a striped dolphin was measured in a pool using standard psycho-acoustic techniques. The go/no-go response paradigm and up-down staircase psychometric method were used. Auditory sensitivity was measured by using 12 narrow-band frequency-modulated signals having center frequencies between 0.5 and 160 kHz. The 50% detection threshold was determined for each frequency. The resulting audiogram for this animal was U-shaped, with hearing capabilities from 0.5 to 160 kHz (8 1/3 oct). Maximum sensitivity (42 dB re 1 microPa) occurred at 64 kHz. The range of most sensitive hearing (defined as the frequency range with sensitivities within 10 dB of maximum sensitivity) was from 29 to 123 kHz (approximately 2 oct). The animal's hearing became less sensitive below 32 kHz and above 120 kHz. Sensitivity decreased by about 8 dB per octave below 1 kHz and fell sharply at a rate of about 390 dB per octave above 140 kHz.
Descriptors: dolphins physiology, pitch discrimination physiology, acoustic stimulation, auditory threshold physiology, fourier analysis, signal processing, computer assisted, sound spectrography.
Kastelein, R.A., W.C. Verboom, M. Muijsers, N.V. Jennings, and S. van der Heul (2005). The influence of acoustic emissions for underwater data transmission on the behaviour of harbour porpoises (Phocoena phocoena) in a floating pen. Marine Environmental Research 59(4): 287-307. ISSN: 0141-1136.
Descriptors: Phocoena phocoena, conservation measures, sound reception, underwater communication system for shipping, behavioral response to sound and conservation relations, avoidance behavior, physical pollution, sound pollution, sound, acoustic emissions for underwater data transmission.
Kijewska, A., Z. Jankowski, I. Kuklik, and J. Rokicki (2003). Pathological changes in the auditory organs of the harbor porpoise (Phocoena phocoena L.) Associated with Stenurus minor (Kuhn, 1829). Acta Parasitologica 48(1): 60-63. ISSN: 1230-2821.
NAL Call Number: QL757.A27
Descriptors: behavior, parasitology, sense organs, sensory reception, auditory malfunction, echo disruption, parasites, harbour porpoise.
Killebrew, D.A., E. Mercado III, L.M. Herman, and A.A. Pack (2001). Sound production of a neonate bottlenose dolphin. Aquatic Mammals 27(1): 34-44. ISSN: 0167-5427.
Descriptors: Tursiops truncatus, young development, acoustic signals, sound production, neonate.
Klishin, V.I. and V.V. Popov (2000). Hearing characteristics of harbour porpoise Phocoena phocoena. Doklady Akademii Nauk 370(3): 413-415. ISSN: 0869-5652.
NAL Call Number: Q60.D64
Descriptors: Phocoena phocoena, sound reception, high frequency sounds, role in echolocation, experimental study, echolocation, sound.
Klishin, V.O. and V.V. Popov (2000). Hearing characteristics of the harbor porpoise Phocoena phocoena. Doklady Biological Sciences Proceedings of the Academy of Sciences of the USSR 370: 7-9. ISSN: 0012-4966.
NAL Call Number: 511 P444AEB
Descriptors: hearing physiology, porpoises physiology, acoustic stimulation.
Notes: Biological sciences sections translated from Russian.
Klishin, V., V. Popov, and A.Y. Supin (2000). Hearing capabilities of a beluga whale, Delphinapterus leucas. Aquatic Mammals 26(3): 212-228. ISSN: 0167-5427.
Descriptors: Delphinapterus leucas, sound reception, hearing capabilities.
Korolev, V.I., K.A. Zaitseva, and V.V. Rotin (1996). Osobennosti struktury ekholokatsionnogo signala del'fina Delphinapterus leucas. [The structural characteristics of the echolocation signal in the beluga whale Delphinapterus leucas]. Zhurnal Evoliutsionnoi Biokhimii i Fiziologii 32(4): 539-42. ISSN: 0044-4529.
Abstract: The sounding signal analysis of beluga dolphin under aquatory adaptation with orientation reflexes has been conducted. It has been shown that the single sounding orientation impulse of beluga has a complex structure. Its initial part consists of a large number of components and has a great power. The main part of impulse is frequency-modulated and has a large duration and constant amplitude. The spectral analysis of beluga's signal demonstrates the low-frequency character with spectrum maximal of 1.6 kHz.
Descriptors: echolocation physiology, whales physiology, dolphins physiology, orientation physiology, sound spectrography statistics and numerical data.
Language of Text: Russian.
Kozak, V.A. (1975). Receptor Zone of the Video-Acoustic System of the Sperm Whale (Physeter Catodon L., 1758), Joint Publications Research Service: Arlington, Va. 6 p.
NAL Call Number: TRANSL 24702
Descriptors: sperm whale, video-acoustic system, receptor zone, Physeter catodon.
Notes: Translated from Russian, JPRS 65017.
Lammers, M.O., W.W. Au, and D.L. Herzing (2003). The broadband social acoustic signaling behavior of spinner and spotted dolphins. Journal of the Acoustical Society of America 114(3): 1629-39. ISSN: 0001-4966.
Abstract: Efforts to study the social acoustic signaling behavior of delphinids have traditionally been restricted to audio-range (<20 kHz) analyses. To explore the occurrence of communication signals at ultrasonic frequencies, broadband recordings of whistles and burst pulses were obtained from two commonly studied species of delphinids, the Hawaiian spinner dolphin (Stenella longirostris) and the Atlantic spotted dolphin (Stenella frontalis). Signals were quantitatively analyzed to establish their full bandwidth, to identify distinguishing characteristics between each species, and to determine how often they occur beyond the range of human hearing. Fundamental whistle contours were found to extend beyond 20 kHz only rarely among spotted dolphins, but with some regularity in spinner dolphins. Harmonics were present in the majority of whistles and varied considerably in their number, occurrence, and amplitude. Many whistles had harmonics that extended past 50 kHz and some reached as high as 100 kHz. The relative amplitude of harmonics and the high hearing sensitivity of dolphins to equivalent frequencies suggest that harmonics are biologically relevant spectral features. The burst pulses of both species were found to be predominantly ultrasonic, often with little or no energy below 20 kHz. The findings presented reveal that the social signals produced by spinner and spotted dolphins span the full range of their hearing sensitivity, are spectrally quite varied, and in the case of burst pulses are probably produced more frequently than reported by audio-range analyses.
Descriptors: dolphins physiology, social behavior, sound spectrography, vocalization, animal physiology, auditory threshold physiology, signal processing, computer assisted, species specificity, ultrasonics.
Lammers, M.O. and W.W.L. Au (2003). Directionality in the whistles of Hawaiian spinner dolphins (Stenella longirostris): A signal feature to cue direction of movement? Marine Mammal Science 19(2): 249-264. ISSN: 0824-0469.
NAL Call Number: QL713.2.M372
Descriptors: Stenella longirostris, acoustic signals, whistles, directionality and significance for group coordination, schooling, cooperative behavior, navigation, north Pacific, Hawaii, Oahu, whistles directionality, significance for group coordination.
Larsen, F. (1999). Kan pingere reducere bifangst af marsvin? [Are acoustic alarms able to reduce bycatch of porpoises?]. Fisk Og Hav. Skrifter Fra Danmarks Fiskeri Og Havundersoegelser 49: 42-53. ISSN: 0105-9211.
Descriptors: porpoises, bycatch, fishing methods, noise, fishing nets, sound, Denmark, catch composition, Cetacea, equipment, Europe, fishing gear, mammals, pollutants, radiation, Scandinavia, western Europe.
Larsen, F. (1997). Effekten af akustiske alarmer paa bifangst af marsvin i garn: rapport om foreloebige resultater. [The effect of acoustic alarms on bycatch of harbour porpoises in gill nets: preliminary results [Phocoena phocoena]]. DFU Rapport (Charlottenlund, Denmark) 44: 15. ISSN: 1395-8216.
Descriptors: porpoises, bycatch, fishing methods, gillnets, sound, noise, Denmark, catch composition, Cetacea, equipment, Europe, fishing gear, fishing nets, mammals, pollutants, radiation, Scandinavia, Western Europe.
Language of Text: Danish summary.
Lees, S., D.B. Hanson, and E.A. Page (1996). Some acoustical properties of the otic bones of a fin whale. Journal of the Acoustical Society of America 99(4, Pt. 1): 2421-7. ISSN: 0001-4966.
Abstract: The otic bones in this report are the tympanic bulla, the periotic, and the three ossicles (malleus, incus, and stapes) of an adult fin whale (Balaenoptera physalus). The purpose was to determine if the periotic was denser than the other otic bones. It was found in one male adult fin whale that the density of all the otic bones is approximately the same, 2.50 kg/m3 with a maximum of 2.58. The lowest density was observed in the stapes (2.36). The sonic velocity seems to vary as the density but there also seems to be a structural effect. The maximum sonic velocity was 4.89 km/s in the malleus. The specific acoustic impedance was as high as 12.5 megarayles in the periotic. These values compare with those for human femur of 1.95 for the density, 3.73 for the sonic velocity, and 7.33 for the specific acoustic impedance. The ossicles weigh as much as 200 times as much as human ossicles. The density of whale ossicles are about ten percent greater than human ossicles. The mechanical natural frequency of the whale ossicles must be very low. The approximate uniformity of the properties of this whale's otic bones may be characteristic of the middle ear. The density of the otic bones of land mammals is less than for whales. The density of the horse petrosal (2.29 g/cc) is essentially the same as the density of adult human ossicles (2.23-2.27 g/cc). The high density of the otic bones for all mammals suggests it may be related to hearing acuity perhaps by increasing the specific acoustic impedance, which increases the acoustic contrast with the other body tissues.
Descriptors: acoustics, ear ossicles physiology, whales physiology.
Lema, S.C. and J.T. Kelly (2002). The production of communication signals at the air-water and water-substrate boundaries. Journal of Comparative Psychology 116(2): 145-50. ISSN: 0735-7036.
Abstract: The 2 interfaces of the aquatic environment, the boundary between air-water and water-substrate, have distinctive physical characteristics that facilitate the production of communication signals. Recent evidence suggests that animals living on or near these boundaries use the interface to generate signals in 2 ways: (a) by producing a signal that propagates along the interface or (b) by producing a signal at the interface that is transmitted and detected within 1 of the component media. By examining the diversity of behaviors used to produce signals at these boundaries, the authors illustrate how human perception of these environments may cause researchers to incorrectly assume the environmental context of signal-generating behaviors and overlook modalities of communication pertinent to the animal.
Descriptors: air, animal communication, behavior, animal, environment, vocalization, animal, water, acoustics, amphibia, fishes, social environment, species specificity, vibration, whales.
Liebschner, A., W. Hanke, L. Miersch, G. Dehnhardt, and M. Sauerland (2005). Sensitivity of a tucuxi (Sotalia fluviatilis guianensis) to airborne sound. Journal of the Acoustical Society of America 117(1): 436-41. ISSN: 0001-4966.
Abstract: Auditory systems of cetaceans are considered highly specialized for underwater sound processing, whereas the extent of their hearing capacity in air is still a point of issue. In this study, the sensitivity to airborne sound in a male tucuxi (Sotalia fluviatilis guianensis) was tested by means of a go/no go response paradigm. Auditory thresholds were obtained from 2 to 31.5 kHz. Compared to the hearing thresholds of other dolphins as well as of amphibian mammals, the sensitivity to airborne sound of the test subject is low from 2 to 8 kHz, with the highest threshold at 4 kHz. Thresholds at 16 and 31.5 kHz reveal a sharp increase in hearing sensitivity. Thus, although not obtained in this study, the upper aerial hearing limit is in the ultrasonic range. A comparison of the present data with the underwater audiogram of the same test subject referred to sound intensity indicates that the sensitivity of Sotalia to underwater sound is generally better than to airborne sound.
Descriptors: air, auditory perception physiology, discrimination psychology, echolocation physiology, auditory threshold physiology, dolphins, hearing physiology, sound.
Lilly, J.C. (1978). Communication Between Man and Dolphin: the Possibilities of Talking With Other Species, Crown Publishers: New York, 269 p. ISBN: 0517530368.
NAL Call Number: QL737.C432L53
Descriptors: dolphins behavior, animal communication, animal intelligence.
Livshits, M.S. (1975). Some Properties of Dolphin Hydrolocator From the Viewpoint of Correlation Hypothesis, Joint Publications Research Service: Arlington, Va., 7 p.
NAL Call Number: TRANSL 24707
Descriptors: dolphin, hydrolocator, correlation, properties.
Notes: Translated from Russian, JPRS 64329.
Madsen, P.T., D.A. Carder, W.W. Au, P.E. Nachtigall, B. Mohl, and S.H. Ridgway (2003). Sound production in neonate sperm whales. Journal of the Acoustical Society of America 113(6): 2988-91. ISSN: 0001-4966.
Descriptors: animal communication, animals, newborn physiology, echolocation physiology, vocalization, animal physiology, whales physiology, larynx physiology, nasal cavity physiology, sound spectrography.
Madsen, P.T., D.A. Carder, W.W.L. Au, P.E. Nachtigall, B. Mohl, and S.H. Ridgway (2003). Sound production in neonate sperm whales (L.). Journal of the Acoustical Society of America 113(6): 2988-2991. ISSN: 0001-4966.
Descriptors: Physeter macrocephalus, acoustic signals, neonate clicks, acoustic data, implications for sound production and function.
Madsen, P.T., M. Johnson, N.A. de Soto, W.M. Zimmer, and P. Tyack (2005). Biosonar performance of foraging beaked whales (Mesoplodon densirostris). Journal of Experimental Biology 208(2): 181-94. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Abstract: Toothed whales (Cetacea, odontoceti) emit sound pulses to probe their surroundings by active echolocation. Non-invasive, acoustic Dtags were placed on deep-diving Blainville's beaked whales (Mesoplodon densirostris) to record their ultrasonic clicks and the returning echoes from prey items, providing a unique view on how a whale operates its biosonar during foraging in the wild. The process of echolocation during prey capture in this species can be divided into search, approach and terminal phases, as in echolocating bats. The approach phase, defined by the onset of detectable echoes recorded on the tag for click sequences terminated by a buzz, has interclick intervals (ICI) of 300-400 ms. These ICIs are more than a magnitude longer than the decreasing two-way travel time to the targets, showing that ICIs are not given by the two-way-travel times plus a fixed, short lag time. During the approach phase, the received echo energy increases by 10.4(+/-2) dB when the target range is halved, demonstrating that the whales do not employ range-compensating gain control of the transmitter, as has been implicated for some bats and dolphins. The terminal/buzz phase with ICIs of around 10 ms is initiated when one or more targets are within approximately a body length of the whale (2-5 m), so that strong echo returns in the approach phase are traded for rapid updates in the terminal phase. It is suggested that stable ICIs in the search and approach phases facilitate auditory scene analysis in a complex multi-target environment, and that a concomitant low click rate allows the whales to maintain high sound pressure outputs for prey detection and discrimination with a pneumatically driven, bi-modal sound generator.
Descriptors: appetitive behavior physiology, echolocation physiology, feeding behavior physiology, whales physiology, acoustics, Atlantic Ocean, sound spectrography.
Madsen, P.T., I. Kerr, and R. Payne (2004). Echolocation clicks of two free-ranging, oceanic delphinids with different food preferences: false killer whales Pseudorca crassidens and Risso's dolphins Grampus griseus. Journal of Experimental Biology 207(11): 1811-23. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Abstract: Toothed whales (Odontoceti, Cetacea) navigate and locate prey by means of active echolocation. Studies on captive animals have accumulated a large body of knowledge concerning the production, reception and processing of sound in odontocete biosonars, but there is little information about the properties and use of biosonar clicks of free-ranging animals in offshore habitats. This study presents the first source parameter estimates of biosonar clicks from two free-ranging oceanic delphinids, the opportunistically foraging Pseudorca crassidens and the cephalopod eating Grampus griseus. Pseudorca produces short duration (30 micro s), broadband (Q=2-3) signals with peak frequencies around 40 kHz, centroid frequencies of 30-70 kHz, and source levels between 201-225 dB re. 1 micro Pa (peak to peak, pp). Grampus also produces short (40 micro s), broadband (Q=2-3) signals with peak frequencies around 50 kHz, centroid frequencies of 60-90 kHz, and source levels between 202 and 222 dB re. 1 micro Pa (pp). On-axis clicks from both species had centroid frequencies in the frequency range of most sensitive hearing, and lower peak frequencies and higher source levels than reported from captive animals. It is demonstrated that sound production in these two free-ranging echolocators is dynamic, and that free-ranging animals may not always employ biosonar signals comparable to the extreme signal properties reported from captive animals in long-range detection tasks. Similarities in source parameters suggest that evolutionary factors other than prey type determine the properties of biosonar signals of the two species. Modelling shows that interspecific detection ranges of prey types differ from 80 to 300 m for Grampus and Pseudorca, respectively.
Descriptors: animal communication, dolphins physiology, feeding behavior physiology, models, biological, sound, Indian Ocean, sound spectrography, time factors.
Madsen, P.T., I. Kerr, and R. Payne (2004). Source parameter estimates of echolocation clicks from wild pygmy killer whales (Feresa attenuata) (L). Journal of the Acoustical Society of America 116(4 ): 1909-1912; (Pt. 1). ISSN: 0001-4966.
Descriptors: Feresa attenuata, echolocation, north Indian Ocean, echolocation clicks, source parameter estimates.
Madsen, P.T., M. Wahlberg, and B. Mohl (2002). Male sperm whale (Physeter macrocephalus) acoustics in a high-latitude habitat: implications for echolocation and communication. Behavioral Ecology and Sociobiology 53(1): 31-41. ISSN: 0340-5443.
NAL Call Number: QL751.B4
Descriptors: behavior, communication, acoustic communication, echolocation, habitat, latitude, prey location, sound pressure.
Marten, K., K.S. Norris, P.W.B. Moore, and K.A. England (1988). Loud impulse sounds in Odontocete predation and social behaviour. NATO ASI (Advanced Science Institutes) Series. Series A. Life Sciences No. 156: 567-579. ISSN: 0161-0449.
NAL Call Number: QH301.N32
Descriptors: Pisces, predators, Odontoceti, predator loud impulse sounds, possible role in predation.
Martin, S.W., M. Phillips, E.J. Bauer, P.W. Moore, and D.S. Houser (2005). Instrumenting free-swimming dolphins echolocating in open water. Journal of the Acoustical Society of America 117(4): 2301-2307; (Pt. 1). ISSN: 0001-4966.
Descriptors: Delphinidae, activity recording, monitoring underwater position and attitude, sound recording techniques, biosonar measurement tool, monitoring underwater echolocation signals.
Masters, W.M. and H.E. Harley (2003). Performance and cognition in echolocating mammals. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 249-259. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Odontoceti, micro-Chiroptera, echolocation, signals characterization, performance and cognitive aspects, review, intelligence.
McCowan, B. and D. Reiss (2001). The fallacy of 'signature whistles' in bottlenose dolphins: a comparative perspective of 'signature information' in animal vocalizations. Animal Behaviour 62(6): 1151-1162. ISSN: 0003-3472.
NAL Call Number: 410 B77
Descriptors: communication between animals, species, vocalization, dolphins, Tursiops truncatus.
McCowan, B. and D. Reiss (1995). Maternal aggressive contact vocalizations in captive bottlenose dolphins (Tursiops truncatus): wide-band, low-frequency signals during mother/aunt-infant interactions. Zoo Biology 14(4): 293-309. ISSN: 0733-3188.
NAL Call Number: QL77.5.Z6
Abstract: The mother-infant bond in bottlenose dolphins is critical to infant survival and has been reported to last from 3-10 years in both captive and wild populations. Little information on mother-infant communication during early development has been collected. This paper reports on a newly discovered dolphin vocalization, termed thunk, which is predominantly used by mothers toward infants. Four mother-infant pairs and one aunt-infant pair were the subjects for this study, Methods included a focal animal sampling technique using 2.5 min interval and event/continuous sampling regimes on audio- or videotape. Results indicated that thunks are produced by mothers or aunting females during infant departures (distances greater than 5 feet) and are frequently followed by disciplinary activity by the mother or aunt. In addition, thunks appeared to cease at approximately 9-10 months after birth, concurrent with a decrease in infant dependence. Thunks also were analyzed acoustically for frequency and duration parameters. Thunks have a harmonic structure with an energy peak in the 273-350 Hz range and ranged from 129-5,556 Hz in frequency and from 21-171 ms in duration. They appear to function as aggressive contact vocalizations produced by mothers and other adult females toward infants in order to maintain infant proximity.
Descriptors: behavior, communication, development, ecology, environmental sciences, reproductive system, reproduction, development, disciplinary behavior, infant proximity, mother infant communication.
McDonald, M.A., J. Calambokidis, A.M. Teranishi, and J.A. Hildebrand (2001). The acoustic calls of blue whales off California with gender data. Journal of the Acoustical Society of America 109(4): 1728-35. ISSN: 0001-4966.
Abstract: The acoustic calls of blue whales off California are described with visual observations of behavior and with acoustic tracking. Acoustic call data with corresponding position tracks are analyzed for five calling blue whales during one 100-min time period. Three of the five animals produced type A-B calls while two produced another call type which we refer to as type D. One of the animals producing the A-B call type was identified as male. Pauses in call production corresponded to visually observed breathing intervals. There was no apparent coordination between the calling whales. The average call source level was calculated to be 186 dB re: 1 muPa at 1 m over the 10-110-Hz band for the type B calls. On two separate days, female blue whales were observed to be silent during respective monitoring periods of 20 min and 1 h.
Descriptors: vocalization, animal physiology, whales physiology, sex factors.
Mellinger, D.K. and C.W. Clark (2000). Recognizing transient low-frequency whale sounds by spectrogram correlation. Journal of the Acoustical Society of America 107(6): 3518-29. ISSN: 0001-4966.
Abstract: A method is described for the automatic recognition of transient animal sounds. Automatic recognition can be used in wild animal research, including studies of behavior, population, and impact of anthropogenic noise. The method described here, spectrogram correlation, is well-suited to recognition of animal sounds consisting of tones and frequency sweeps. For a sound type of interest, a two-dimensional synthetic kernel is constructed and cross-correlated with a spectrogram of a recording, producing a recognition function--the likelihood at each point in time that the sound type was present. A threshold is applied to this function to obtain discrete detection events, instants at which the sound type of interest was likely to be present. An extension of this method handles the temporal variation commonly present in animal sounds. Spectrogram correlation was compared to three other methods that have been used for automatic call recognition: matched filters, neural networks, and hidden Markov models. The test data set consisted of bowhead whale (Balaena mysticetus) end notes from songs recorded in Alaska in 1986 and 1988. The method had a success rate of about 97.5% on this problem, and the comparison indicated that it could be especially useful for detecting a call type when relatively few (5-200) instances of the call type are known.
Descriptors: sound, vocalization, animal physiology, auditory threshold physiology, models, biological, sound spectrography methods, whales physiology.
Mercado III, E.F.L.N. (1999). Environmental constraints on sound transmission by humpback whales. Journal of the Acoustical Society of America 106(5): 3004-16. ISSN: 0001-4966.
Abstract: Singing humpback whales in Hawaii produce a variety of sounds at high source levels (ca. 185 dB re: 1 microPa), in coastal waters 15-500 m deep. These sounds are attenuated and distorted as they propagate away from a singer, limiting the utilizable range of the sounds. In the current study, simulations based on normal-mode theory were used to investigate how the effects of shallow-water propagation constrain humpback whales' use of sound. It is shown that humpbacks can greatly affect transmission range by adjusting their positions and sounds in response to environmental factors. Source depth, in particular, is shown to be a major determinant of which frequencies propagate the farthest. A preliminary analysis of range-dependent distortion suggests that spectral cues can potentially provide listening whales with information about how far a sound has traveled.
Descriptors: environment, sound, vocalization, animal physiology, models, biological, whales.
Mercado III, E., L.M. Herman, and A.A. Pack (2003). Stereotypical sound patterns in humpback whale songs: usage and function. Aquatic Mammals 29(1): 37-52. ISSN: 0167-5427.
Descriptors: Megaptera novaeangliae, acoustic signals, song, characteristics, north Pacific, Hawaii, Kawaihae Island, song characteristics, duration, patterns, use and functional analysis.
Miksis, J.L., M.D. Grund, D.P. Nowacek, A.R. Solow, R.C. Connor, and P.L. Tyack (2001). Cardiac responses to acoustic playback experiments in the captive bottlenose dolphin (Tursiops truncatus). Journal of Comparative Psychology 115(3): 227-32. ISSN: 0735-7036.
Abstract: Acoustic recordings were used to investigate the cardiac responses of a captive dolphin (Tursiops truncatus) to sound playback stimuli. A suction-cup hydrophone placed on the ventral midline of the dolphin produced a continuous heartbeat signal while the dolphin was submerged. Heartbeats were timed by applying a matched-filter to the phonocardiogram. Significant heart rate accelerations were observed in response to playback stimuli involving conspecific vocalizations compared with baseline rates or tank noise playbacks. This method documents that objective psychophysiological measures can be obtained for physically unrestrained cetaceans. In addition, the results are the 1st to show cardiac responses to acoustic stimuli from a cetacean at depth. Preliminary evidence suggests that the cardiac response patterns of dolphins are consistent with the physiological defense and startle responses in terrestrial mammals and birds.
Descriptors: auditory perception, heart rate physiology, acoustics, behavior, animal physiology, dolphins physiology, random allocation, vocalization, animal.
Miksis, J.L., P.L. Tyack, and J.R. Buck (2002). Captive dolphins, Tursiops truncatus, develop signature whistles that match acoustic features of human-made model sounds. Journal of the Acoustical Society of America 112(2): 728-739. ISSN: 0001-4966.
Descriptors: Tursiops truncatus, mimicry, learning, acoustic signals, signature whistles, captive and wild specimen comparisons, matching of human made sounds by captives.
Miller, P.J., M.P. Johnson, and P.L. Tyack (2004). Sperm whale behaviour indicates the use of echolocation click buzzes 'creaks' in prey capture. Proceedings of the Royal Society of London. Series B. Biological Sciences 271(1554): 2239-2247. ISSN: 0962-8452.
Abstract: During foraging dives, sperm whales (Physeter macrocephalus) produce long series of regular clicks at 0.5-2 s intervals interspersed with rapid-click buzzes called 'creaks'. Sound, depth and orientation recording Dtags were attached to 23 whales in the Ligurian Sea and Gulf of Mexico to test whether the behaviour of diving sperm whales supports the hypothesis that creaks are produced during prey capture. Sperm whales spent most of their bottom time within one or two depth bands, apparently feeding in vertically stratified prey layers. Creak rates were highest during the bottom phase: 99.8% of creaks were produced in the deepest 50% of dives, 57% in the deepest 15% of dives. Whales swam actively during the bottom phase, producing a mean of 12.5 depth inflections per dive. A mean of 32% of creaks produced during the bottom phase occurred within 10 s of an inflection (13 x more than chance). Sperm whales actively altered their body orientation throughout the bottom phase with significantly increased rates of change during creaks, reflecting increased manoeuvring. Sperm whales increased their bottom foraging time when creak rates were higher. These results all strongly support the hypothesis that creaks are an echolocation signal adapted for foraging, analogous to terminal buzzes in taxonomically diverse echolocating species.
Descriptors: Physeter macrocephalus, echolocation, behavioral evidence for function of creak sounds in prey capture, Gulf of Mexico and Mediterranean Sea, foraging, aquatic diving, vertical distribution, diving depth, Gulf of Mexico, Mediterranean Sea, Ligurian Sea, echolocation function of creak sound emissions, behavioral evidence.
Mobley Jr., J.R. (2005). Assessing responses of humpback whales to North Pacific Acoustic Laboratory (NPAL) transmissions: results of 2001--2003 aerial surveys north of Kauai. Journal of the Acoustical Society of America 117(3, Pt. 2): 1666-1673. ISSN: 0001-4966.
Abstract: Eight aerial surveys were flown north of the Hawaiian island of Kauai during 2001 when the North Pacific Acoustic Laboratory (NPAL) source was not transmitting, and during 2002 and 2003 when it was. All surveys were performed during the period of peak residency of humpback whales (Feb-Mar). During 2002 and 2003, surveys commenced immediately upon cessation of a 24-h cycle of transmissions. Numbers and distribution of whales observed within 40 km of the NPAL source during 2001 (source off) were compared with those observed during 2002 and 2003 (source on). A total of 75 sightings was noted during 2001, as compared with 81 and 55 during 2002 and 2003, respectively. Differences in sighting rates (sightings/km) across years were not statistically significant. Assessment of distributional changes relied upon comparisons of three measures: (a) location depths; (b) distance from the NPAL source; and (c) distance offshore. None of the distributional comparisons revealed statistically significant differences across years. Several possible interpretations are examined: (a) whales have habituated to the NPAL signal; (b) insufficient statistical power exists in the present design to detect any effects; and (c) the effects are short-lived and become undetectable shortly after the cessation of transmissions.
Descriptors: humpback whales, NPAL, responses, sightings, acoustic, transmissions, north Pacific, arial surveys, responses.
Moehl, B. (1992). Narhvaler ogden akustiske Big-Bang hypotese. [Narwhales and the acoustic Big-Bang hypothesis [SONAR]]. In: Aarsskrift, 1992, Ny Carlsbergfondet: Frederiksborgmuseet, Denmark, p. 18-24. ISBN: 87-7245-509-8.
Descriptors: whales, sound, foraging, behavior, ultrasonics, echosounding, measurement, communication technology, identification, Cetacea, mammals, measurement, radiations, sound.
Language of Text: Danish.
Mohl, B. (2001). Sound transmission in the nose of the sperm whale Physeter catodon. A post mortem study. Journal of Comparative Physiology. A, Sensory, Neural, and Behavioral Physiology 187(5): 335-40. ISSN: 0340-7594.
NAL Call Number: QP33.J68
Abstract: During a sperm whale stranding at Romo, the Wadden Sea, Denmark, on 4 December 1997, we were notified in time to start acoustic transmission measurements in the spermaceti complex 1 h after the specimen was seen alive. Frequency-modulated sound pulses, sweeping from 30 kHz to 10 kHz in 25 ms, were injected at the frontal surface at two positions: at the distal sac, and at the center of the junk (a compartmentalized structure below the spermaceti organ). A hydrophone next to the projector served as receiver. The analyses of the recordings show a repetitive, decaying reflection pattern at both projection sites, reminiscent of the multi-pulse click peculiar to sperm whales, although with minor differences in the duration of the intra-click intervals. This experimental evidence supports the Norris and Harvey (1972) theory of click generation in the spermaceti organ. Accordingly, the click is composed of a primary event, followed by a train of reflected pulses, spaced by the time required for the event to travel back and forth between air sacs (reflectors) at each end of the organ. The results also show that the junk readily transmits sound and probably is in acoustic contact with the spermaceti organ.
Descriptors: echolocation physiology, whales physiology, fatty acids physiology, fatty alcohols, nose anatomy and histology, nose physiology.
Mohl, B., W.W. Au, J. Pawloski, and P.E. Nachtigall (1999). Dolphin hearing: relative sensitivity as a function of point of application of a contact sound source in the jaw and head region. Journal of the Acoustical Society of America 105(6): 3421-4. ISSN: 0001-4966.
Abstract: The auditory input area of the dolphin head was investigated in an unrestrained animal trained to beach itself and to accept noninvasive electroencephalograph (EEG) electrodes for the recording of the auditory brain-stem response (ABR). The stimulus was a synthetic dolphin click, transmitted from a piezo-electric transducer and coupled to the skin via a small volume of water. The results conform with earlier experiments on acute preparations that show best auditory sensitivity at the middle of the lower jaw. Minimum latency was found at the rear of the lower jaw. A shaded receiver configuration for the dolphin ear is proposed.
Descriptors: echolocation physiology, head physiology, hearing physiology, jaw physiology, porpoises physiology, sound, electroencephalography, evoked potentials, auditory, brain stem physiology.
Mohl, B., M. Wahlberg, P.T. Madsen, A. Heerfordt, and A. Lund (2003). The monopulsed nature of sperm whale clicks. Journal of the Acoustical Society of America 114(2): 1143-54. ISSN: 0001-4966.
Abstract: Traditionally, sperm whale clicks have been described as multipulsed, long duration, nondirectional signals of moderate intensity and with a spectrum peaking below 10 kHz. Such properties are counterindicative of a sonar function, and quite different from the properties of dolphin sonar clicks. Here, data are presented suggesting that the traditional view of sperm whale clicks is incomplete and derived from off-axis recordings of a highly directional source. A limited number of assumed on-axis clicks were recorded and found to be essentially monopulsed clicks, with durations of 100 micros, with a composite directionality index of 27 dB, with source levels up to 236 dB re: 1 microPa (rms), and with centroid frequencies of 15 kHz. Such clicks meet the requirements for long-range biosonar purposes. Data were obtained with a large-aperture, GPS-synchronized array in July 2000 in the Bleik Canyon off Vesteralen, Norway (69 degrees 28' N, 15 degrees 40' E). A total of 14 h of sound recordings was collected from five to ten independent, simultaneously operating recording units. The sound levels measured make sperm whale clicks by far the loudest of sounds recorded from any biological source. On-axis click properties support previous work proposing the nose of sperm whales to operate as a generator of sound.
Descriptors: ultrasonics, vocalization, animal, acoustics, time factors, whales.
Mohl, B., M. Wahlberg, P.T. Madsen, L.A. Miller, and A. Surlykke (2000). Sperm whale clicks: directionality and source level revisited. Journal of the Acoustical Society of America 107(1): 638-48. ISSN: 0001-4966.
Abstract: In sperm whales (Physeter catodon L. 1758) the nose is vastly hypertrophied, accounting for about one-third of the length or weight of an adult male. Norris and Harvey [in Animal Orientation and Navigation, NASA SP-262 (1972), pp. 397-417] ascribed a sound-generating function to this organ complex. A sound generator weighing upward of 10 tons and with a cross-section of 1 m is expected to generate high-intensity, directional sounds. This prediction from the Norris and Harvey theory is not supported by published data for sperm whale clicks (source levels of 180 dB re 1 microPa and little, if any, directionality). Either the theory is not borne out or the data is not representative for the capabilities of the sound-generating mechanism. To increase the amount of relevant data, a five-hydrophone array, suspended from three platforms separated by 1 km and linked by radio, was deployed at the slope of the continental shelf off Andenes, Norway, in the summers of 1997 and 1998. With this system, source levels up to 223 dB re 1 microPa peRMS were recorded. Also, source level differences of 35 dB for the same click at different directions were seen, which are interpreted as evidence for high directionality. This implicates sonar as a possible function of the clicks. Thus, previously published properties of sperm whale clicks underestimate the capabilities of the sound generator and therefore cannot falsify the Norris and Harvey theory.
Descriptors: animal communication, whales physiology, behavior, animal physiology, models, biological.
Moreno, P., C. Kamminga and A.B. Cohen Stuart (2003). Clicks produced by captive Amazon River dolphins (Inia geoffrensis) in sexual context. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 419-425. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Inia geoffrensis, echolocation, reproductive behavior, acoustic signals, ultrasonic clicks characterization during sexual interaction between males in captivity.
Nachtigall, P.E., J.L. Pawloski, and W.W. Au (2003). Temporary threshold shifts and recovery following noise exposure in the Atlantic bottlenosed dolphin (Tursiops truncatus). Journal of the Acoustical Society of America 113(6): 3425-9. ISSN: 0001-4966.
Abstract: Behaviorally determined hearing thresholds for a 7.5-kHz tone for an Atlantic bottlenosed dolphin (Tursiops truncatus) were obtained following exposure to fatiguing low-frequency octave band noise. The fatiguing stimulus ranged from 4 to 11 kHz and was gradually increased in intensity to 179 dB re 1 microPa and in duration to 55 min. Exposures occurred no more frequently than once per week. Measured temporary threshold shifts averaged 11 dB. Threshold determination took at least 20 min. Recovery was examined 360, 180, 90, and 45 min following exposure and was essentially complete within 45 min.
Descriptors: animal communication, auditory fatigue, echolocation, noise adverse effects, vocalization, animal, acoustic stimulation, auditory threshold, Hawaii, sound spectrography.
Nachtigall, P.E., D.W. Lemonds and H.L. Roitblat (2000). Psychoacoustic studies of dolphin and whale hearing. In: W.W.L. Au, A.N. Popper and R.R. Fay (Editors), Hearing by Whales and Dolphins, Springer Handbook of Auditory Research, p. 330-363. ISBN: 0387949062.
NAL Call Number: QL737.C432H43 2000
Descriptors: Cetacea, literature review, physiological techniques, psychoacoustic studies of hearing, sound reception, hearing, psychoacoustic studies, review.
Nakamura, K., T. Akamatsu, and K. Shimazaki (1998). Threat clicks of captive harbor porpoises, Phocoena phocoena. Bulletin of the Faculty of Fisheries Hokkaido University 49(3): 91-105. ISSN: 0018-3458.
NAL Call Number: 414.9 H682
Descriptors: Phocoena, communication between animals, sound, acoustic properties, aggressive behavior, captivity, behavior, chemicophysical properties, radiation.
Language of Text: English and Japanese summaries.
Nakamura, K. and T. Akamatsu (2003). Comparison of click characteristics among odontocete species. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 36-40. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Odontoceti, echolocation, click characteristics species comparison and evolution, convergence, phylogeny.
Nakasai, K. and A. Takemura (1975). Studies on the underwater sound, 6: On the underwater calls of fresh water dolphins in South America. Bulletin of the Faculty of Fisheries Nagasaki University (40): 7-13.
Descriptors: sound, under water, studies, fresh water, dolphins, calls, South America.
Language of Text: English summary.
Noad, M.J., D.H. Cato, M.M. Bryden, M.N. Jenner, and K.C. Jenner (2000). Cultural revolution in whale songs. Nature (London) 408(6812): 537. ISSN: 0028-0836.
NAL Call Number: 472 N21
Descriptors: vocalization, animal, whales physiology, learning.
Norris, K.S. and B. Mohl (1983). Can odontocetes debilitate prey with sound? Possible acoustic stunning, cetaceans. American Naturalist 122(1): 85-104. ISSN: 0003-0147.
NAL Call Number: 470 AM36
Descriptors: Odontocetes, prey, debilitate, sound, acoustic stunning, cetaceans.
Nummela, S., S. Bajpai, and J.G.M. Thewissen (2003). Hearing in eocene whales (Cetacea, Mammalia). Journal of Vertebrate Paleontology 23(3, Suppl.): 83A. ISSN: 0272-4634.
Descriptors: evolution and adaptation, paleobiology, sense organs, sensory reception, derived characters, sound reception, airborne, waterborne, hearing, Cetacea, whales.
Notes: Meeting Information: Sixty-Third Annual Meeting of the Society of Vertebrate Paleontology, St. Paul, MN, USA, 2003.
Nummela, S., J.G.M. Thewissen, and S. Bajpai (2004). Evolution of underwater hearing in whales. Journal of Morphology 260(3): 317. ISSN: 0362-2525.
NAL Call Number: 444.8 J826
Descriptors: evolution and adaptation, sense organs, sensory reception, echolocation, underwater hearing.
Notes: Meeting Information: Seventh International Congress of Vertebrate Morphology, Boca Raton, FL, USA, 2004.
Olesiuk, P.F., L.M. Nichol, M.J. Sowden, and J.K.B. Ford (2002). Effect of the sound generated by an acoustic harassment device on the relative abundance and distribution of harbor porpoises (Phocoena phocoena) in retreat passage, British Columbia. Marine Mammal Science 18(4): 843-862. ISSN: 0824-0469.
NAL Call Number: QL713.2.M372
Descriptors: wildlife management, conservation, acoustic harassment device, field equipment, relative abundance, sound effects, species distribution, harbour porpoise.
Oleson, E.M., J. Barlow, J. Gordon, S. Rankin, and J.A. Hildebrand (2003). Low frequency calls of Bryde's whales. Marine Mammal Science 19(2): 407-419. ISSN: 0824-0469.
NAL Call Number: QL713.2.M372
Descriptors: Balaenoptera edeni, acoustic signals, north Pacific, west Pacific, Caribbean Sea, Japan, low frequency calls analysis.
Oschman, N.H., K.E. Sommers and J.L. Oschman (2000). Method and Apparatus for Temporarily Debilitating Tuna and Other Fish to Facilitate Capture, Nature' s Own Research Assoc., Dover, New Hampshire (USA): Makati City (Philippines). Bp-Ipo, 35 p.
Abstract: Tuna are separated from dolphins who often travel together by temporarily stunning the tuna and allowing the dolphins to continue on course. The tuna stunning is accomplished by creating underwater sounds of a selected frequency range which has a maximum impact on the tuna and a minimum impact on the dolphins.
Descriptors: tuna, capture of animals, sound, methods, equipment, fishes, radiation, saltwater fishes.
Language of Text: English summary.
Oswald, J.N., J. Barlow, and T.F. Norris (2003). Acoustic identification of nine delphinid species in the eastern tropical Pacific Ocean. Marine Mammal Science 19(1): 20-37. ISSN: 0824-0469.
NAL Call Number: QL713.2.M372
Descriptors: Delphinidae, identification techniques, acoustic identification, evaluation, acoustic signals, east Pacific, tropical region, acoustic identification evaluation.
Oswald, J.N., S. Rankin, and J. Barlow (2004). The effect of recording and analysis bandwidth on acoustic identification of Delphinid species. Journal of the Acoustical Society of America 116(5): 3178-3185. ISSN: 0001-4966.
Descriptors: Delphinus delphis, Stenella attenuata, Stenella coeruleoalba, Stenella longirostris, identification techniques, ability, acoustic signals, Pacific Ocean, acoustic identification, effect of recording and analysis bandwidth.
Pack, A. and L.M. Herman (1995). Sensory integration in the bottlenosed dolphin: immediate recognition of complex shapes across the senses of echolocation and vision. Journal of the Acoustical Society of America 98(2, Pt. 1): 722-733. ISSN: 0001-4966.
Descriptors: behavior, communication, nervous system, neural coordination, sense organs, sensory reception, cross modal tests, matching to sample test, object recognition, perception, shape discrimination.
Pack, A.A., L.M. Herman and M. Hoffmann Kuhnt (2003). Dolphin echolocation shape perception: from sound to object. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 288-298. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Tursiops truncatus, echolocation, object recognition and shape perception.
Philips, J.D., P.E. Nachtigall, W.W.L. Au, J.L. Pawloski and H.L. Roitblat (2003). Echolocation in the Risso's dolphin, Grampus griseus: a preliminary report. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 43-50. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Grampus griseus, echolocation, characteristics.
Philips, J.D., P.E. Nachtigall, W.W.L. Au, J.L. Pawloski, and H.L. Roitblat (2003). Echolocation in the Risso's dolphin, Grampus griseus. Journal of the Acoustical Society of America 113(1): 605-616. ISSN: 0001-4966.
Descriptors: Grampus griseus, sound recording techniques, echolocation, orientation, north Pacific, Hawaii, Kaneohe Bay, echolocation signals analysis.
Pilleri, G. (1983). The sonar system of the dolphins. Endeavour 7(2): 59-64. ISSN: 0013-7162.
NAL Call Number: 472 EN2
Descriptors: dolphins, sonar system.
Popov, V.V. (2003). The properties of cetacean hearing. I. The range of perceived frequencies and frequency selectivity. Sensornye Sistemy 17(3): 179-197. ISSN: 0235-0092.
Descriptors: behavior, nervous system, neural coordination, sense organs, sensory reception, hearing test, applied and field techniques, Cetacean hearing, frequency selectivity, perceived frequency range, psychophysics, cetaceans.
Popov, V.V. (2003). The properties of Cetacean hearing. II. Temporal resolution. Sensornye Sistemy 17(4): 275-287. ISSN: 0235-0092.
Descriptors: sense organs, sensory reception, behavior, echolocation, electrophysiology, envelope following response, gap in noise detection, hearing, cetaceans, modulation transfer function, recovery cycle, short latency auditory evoked response, temporal integration, temporal resolution, temporal summation.
Popov, V.V. and A.Y. Supin (2001). Contribution of various frequency bands to ABR in dolphins. Hearing Research 151(1-2): 250-260. ISSN: 0378-5955.
Abstract: Auditory brainstem responses (ABR) to clicks and noise bursts of various frequency bands and intensities were recorded in two bottlenosed dolphins, Tursiops truncatus. The purpose was to assess contributions of various parts of the cochlear partition to ABR and travelling wave velocity in the cochlea. At band-pass filtered stimuli (1-0.25 oct wide), ABR amplitude increased with increasing stimulus frequency, thus indicating higher contribution of basal cochlear parts. At high-pass and low-pass filtered stimuli, ABR amplitude increased with passband widening. However, the sum of all narrow-band contributions was a waveform of higher amplitude than the real ABR evoked by the wide-band stimulus. Applying a correction based on an assumption that the 'internal spectrum' is about 0.4 oct wider than the nominal stimulus spectrum resulted in the sum of narrow-band contributions equal to the wide-band ABR. The travelling wave velocity was computed based on ABR latencies and assigned a frequency of 128 kHz to the basal end of the cochlea. The computation gave values from 38.2 oct/ms at the proximal end of the basilar membrane to 4.0 oct/ms at a distance of 3.25 oct (13.5 kHz).
Descriptors: dolphins physiology, evoked potentials, auditory, brain stem physiology, acoustic stimulation, cochlea physiology, noise.
Popov, V.V. and A.Y. Supin (1998). Auditory evoked responses to rhythmic sound pulses in dolphins. Journal of Comparative Physiology. A, Sensory, Neural, and Behavioral Physiology 183(4): 519-24. ISSN: 0340-7594.
NAL Call Number: QP33.J68
Abstract: The ability of auditory evoked potentials to follow sound pulse (click or pip) rate was studied in bottlenosed dolphins. Sound pulses were presented in 20-ms rhythmic trains separated by 80-ms pauses. Rhythmic click or pip trains evoked a quasi-sustained response consisting of a sequence of auditory brainstem responses. This was designated as the rate-following response. Rate following response peak-to-peak amplitude dependence on sound pulse rate was almost flat up to 200 s-1, then displayed a few peaks and valleys superimposed on a low-pass filtering function with a cut-off frequency of 1700 s-1 at a 0.1-amplitude level. Peaks and valleys of the function corresponded to the pattern of the single auditory brain stem response spectrum; the low-pass cut-off frequency was below the auditory brain stem response spectrum bandwidth. Rate-following response frequency composition (magnitudes of the fundamental and harmonics) corresponded to the auditory brain stem response frequency spectrum except for lower fundamental magnitudes at frequencies above 1700 Hz. These regularities were similar for both click and pip trains. The rate-following response to steady-state rhythmic stimulation was similar to the rate-following response evoked by short trains except for a slight amplitude decrease with the rate increase above 10 s-1. The latter effect is attributed to a long-term rate-dependent adaptation in conditions of the steady-state pulse stimulation.
Descriptors: dolphins physiology, evoked potentials, auditory physiology, acoustic stimulation, evoked potentials, auditory, brain stem physiology, vibration.
Popov, V.V., A.Y. Supin, and V.O. Klishin (1997). Frequency tuning of the dolphin's hearing as revealed by auditory brain-stem response with notch-noise masking. Journal of the Acoustical Society of America 102(6): 3795-801. ISSN: 0001-4966.
Abstract: Notch-noise masking was used to measure frequency tuning in a dolphin (Tursiops truncatus) in a simultaneous-masking paradigm in conjunction with auditory brain-stem evoked potential recording. Measurements were made at probe frequencies of 64, 76, 90, and 108 kHz. The data were analyzed by fitting the rounded-exponent model of the auditory filters to the experimental data. The fitting parameter values corresponded to the filter tuning as follows: QER (center frequency divided by equivalent rectangular bandwidths) of 35 to 36.5 and Q10 dB of 18 to 19 at all tested frequencies.
Descriptors: dolphins physiology, evoked potentials, auditory, brain stem, hearing physiology, noise, perceptual masking, acoustic stimulation, models, biological.
Popov, V.V., A.Y. Supin, V.O. Klishin, and T.M. Bulgakova (2003). Sensitivity of dolphin's hearing as a function of the sound-source position. Doklady Biological Sciences. Proceedings of the Academy of Sciences of the USSR 392: 393-6. ISSN: 0012-4966.
NAL Call Number: 511 P444AEB
Descriptors: auditory perception physiology, dolphins physiology, echolocation physiology, acoustic stimulation, audiometry, evoked response, audiometry, pure tone, auditory threshold, evoked potentials, auditory physiology.
Notes: Biological sciences sections translated from Russian.
Popov, V.V., Supin A Ya, and V.O. Klishin (2001). Auditory brainstem response recovery in the dolphin as revealed by double sound pulses of different frequencies. Journal of the Acoustical Society of America 110(4): 2227-33. ISSN: 0001-4966.
Abstract: Recovery of auditory brainstem responses (ABR) in a bottlenose dolphin was studied in conditions of double-pip stimulation when two stimuli in a pair differed in frequency and intensity. When the conditioning and test stimuli were of equal frequencies, the test response was markedly suppressed at short interstimulus intervals; complete recovery appeared at intervals from about 2 ms (when two stimuli were of equal intensity) to 10-20 ms (when the conditioning stimulus exceeded the test by up to 40 dB). When the two stimuli were of different frequencies, the suppression diminished and was almost absent at a half-octave difference even if the conditioning stimulus exceeded the test one by 40 dB. Frequency-dependence curves (ABR amplitude dependence on frequency difference between the two stimuli) had equivalent rectangular bandwidth from +/-0.2 oct at test stimuli of 20 dB above threshold to +/-0.5 oct at test stimuli of 50 dB above threshold.
Descriptors: dolphins physiology, evoked potentials, auditory, brain stem physiology, pitch discrimination physiology, acoustic stimulation, auditory threshold physiology, loudness perception physiology.
Popov, V.V., A.Y. Supin, V.O. Klishin, and T.M. Bulgakova (2003). Sensitivity of the Dolphin's hearing as a function of sound-source position. Doklady Akademii Nauk 392(4): 556-559. ISSN: 0869-5652.
Descriptors: Tursiops truncatus, sound reception, sensitivity, interaural imbalance and sound source position significance, sound.
Portfors, C.V. and J.J. Wenstrup (2003). Neural processing of target distance: transformation of combination-sensitive responses. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 141-146. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Pteronotus parnellii, brain, medial geniculate body and inferior colliculus, neural processing of echolocation target distance, echolocation.
Potter, J.R. and E.A. Taylor (2001). On novel reception models for bottlenose dolphin echolocation. Proceedings of the Institute of Acoustics 23(4): 103-112. ISSN: 0309-8117.
Descriptors: Tursiops truncatus, teeth, jaws, echolocation, novel reception models, possible roles of teeth and jaw bone.
Purves, P.E. and G.E. Pilleri (1983). Echolocation in Whales and Dolphins, Academic Press: London; New York, 261 p. ISBN: 0125679602.
NAL Call Number: QL765.P9
Descriptors: echolocation physiology, dolphins, whales.
Rasmussen, M.H., M. Wahlberg, and L.A. Miller (2004). Estimated transmission beam pattern of clicks recorded from free-ranging white-beaked dolphins (Lagenorhynchus albirostris). Journal of the Acoustical Society of America 116(3): 1826-1831. ISSN: 0001-4966.
Descriptors: Lagenorhynchus albirostris, echolocation, acoustic signals, north Atlantic, Iceland, Keflavik, ultrasonic clicks, estimated transmission beam pattern.
Renaud, D.L. and A.N. Popper (1975). Sound localization by the bottlenose porpoise Tursiops truncatus. Journal of Experimental Biology 63(3): 569-85. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Abstract: 1. Sound localization was measured behaviourally for the Atlantic bottlenose porpoise (Tursiops truncatus) using a wide range of pure tone pulses as well as clicks simulating the species echolocation click. 2. Measurements of the minimum audible angle (MAA) on the horizontal plane give localization discrimination thresholds of between 2 and 3 degrees for sounds from 20 to 90 kHz and thresholds from 2-8 to 4 degrees at 6, 10 and 100 kHz. With the azimuth of the animal changed relative to the speakers the MAAs were 1-3-1-5 degrees at an azimuth of 15 degrees and about 5 degrees for an azimuth of 30 degrees. 3. MAAs to clicks were 0-7-0-8 degrees. 4. The animal was able to do almost as well in determining the position of vertical sound sources as it could for horizontal localization. 5. The data indicate that at low frequencies the animal may have been localizing by using the region around the external auditory meatus as a detector, but at frequencies about 20 kHz it is likely that the animal was detecting sounds through the lateral sides of the lower jaw. 6. Above 20 kHz, it is likely that the animal was localizing using binaural intensity cues. 7. Our data support evidence that the lower jaw is an important channel for sound detection in Tursiops.
Descriptors: dolphins physiology, echolocation physiology, orientation physiology, auditory perception physiology.
Rendell, L. and H. Whitehead (2004). Do sperm whales share coda vocalizations? Insights into coda usage from acoustic size measurement. Animal Behaviour 67(5): 865-874. ISSN: 0003-3472.
NAL Call Number: 410 B77
Abstract: Group-specific communication signals are found in many group-living species. One example is group variation in the production of codas, which are short stereotyped patterns of clicks produced in social contexts, by sperm whales, Physeter macrocephalus. However, little is known about how codas are used by groups and individuals. We used the multipulse structure of sperm whale clicks to estimate the size of animals producing codas. Recordings of a single social unit containing nine largely unrelated animals made over a 1-month period yielded 879 codas of 32 distinctive types. We used an automatic technique to measure the interpulse interval of the clicks in these codas because the interpulse interval is closely related to the size of the animal. Ninety-four codas had sufficiently accurate measurements to be included in further analysis. Modes in the distribution of these measurements showed that more than one animal was i producing codas. Comparing the measurements within coda types revealed that several coda types were I produced by more than one animal. Thus, the codas recorded from these animals represent a shared repertoire, whereby coda production is not limited to a single animal and coda types are shared between individuals within the unit.
Descriptors: Physeter macrocephalus, acoustic signals, coda vocalizations, social behavior, north Pacific, south Pacific, Galapagos Islands, sharing of coda vocalizations within social units.
Rhinelander, M.Q. and S.M. Dawson (2004). Measuring sperm whales from their clicks: stability of interpulse intervals and validation that they indicate whale length. Journal of the Acoustical Society of America 115(4): 1826-1831. ISSN: 0001-4966.
Abstract: Multiple pulses can often be distinguished in the clicks of sperm whales (Physeter macrocephalus). Norris and Harvey [in Animal Orientation and Navigation, NASA SP-262 (1972), pp. 397-417] proposed that this results from reflections within the head, and thus that interpulse interval (IPI) is an indicator of head length, and by extrapolation, total length. For this idea to hold, IPIs must be stable within individuals, but differ systematically among individuals of different size. IPI stability was examined in photographically identified individuals recorded repeatedly over different dives, days, and years. IPI variation among dives in a single day and days in a single year was statistically significant, although small in magnitude (it would change total length estimates by <3%). As expected, IPIs varied significantly among individuals. Most individuals showed significant increases in IPIs over several years, suggesting growth. Mean total lengths calculated from published IPI regressions were 13.1 to 16.1 m, longer than photogrammetric estimates of the same whales (12.3 to 15.3 m). These discrepancies probably arise from the paucity of large (12-16 m) whales in data used in published regressions. A new regression is offered for this size range.
Descriptors: Physeter macrocephalus, biometrical techniques, length estimation, use of broadband clicks, acoustic signals, south Pacific, New Zealand, broadband clicks, use in length estimation.
Ridgway, S.H., T.H. Bullock, D.A. Carder, R.L. Seeley, D. Woods, and R. Galambos (1981). Auditory brainstem response in dolphins. Proceedings of the National Academy of Sciences of the United States of America 78(3): 1943-7. ISSN: 0027-8424.
NAL Call Number: 500 N21P
Abstract: We recorded the auditory brainstem response (ABR) in four dolphins (Tursiops truncatus and Delphinus delphis). The ABR evoked by clicks consists of seven waves within 10 msec; two waves often contain dual peaks. The main waves can be identified with those of humans and laboratory mammals; in spite of a much longer path, the latencies of the peaks are almost identical to those of the rat. The dolphin ABR waves increase in latency as the intensity of a sound decreases by only 4 microseconds/decibel(dB) (for clicks with peak power at 66 kHz) compared to 40 microseconds/dB in humans (for clicks in the sonic range). Low-frequency clicks (6-kHz peak power) show a latency increase about 3 times (12 microseconds/dB) as great. Although the dolphin brainstem tracks individual clicks to at least 600 per sec, the latency increases and amplitude decreases with increasing click rates. This effect varies among different waves of the ABR; it is around one-fifth the effect seen in man. The dolphin brain is specialized for handling brief, frequent clicks. A small latency difference is seen between clicks 180 degrees different in phase--i.e., with initial compression vs. initial rarefaction. The ABR can be used to test theories of dolphin sonar signal processing. Hearing thresholds can be evaluated rapidly. Cetaceans that have not been investigated can now be examined, including the great whales, a group for which data are now completely lacking.
Descriptors: brain stem physiology, dolphins physiology, hearing, acoustic stimulation, oscillometry, species specificity.
Ridgway, S.H. and D. Carder (2001). Assessing hearing and sound production in Cetaceans not available for behavioral audiograms: experiences with sperm, pygmy sperm, and gray whales. Aquatic Mammals 27(3): 267-276. ISSN: 0167-5427.
Descriptors: neural coordination, sensory reception, auditory brainstem response, behavioral audiograms, echolocation, field portable systems, hearing, physiology, sound production, gray whale, pygmy sperm whale.
Ridgway, S.H., D.A. Carder, T. Kamolnick, R.R. Smith, C.E. Schlundt, and W.R. Elsberry (2001). Hearing and whistling in the deep sea: depth influences whistle spectra but does not attenuate hearing by white whales (Delphinapterus leucas) (Odontoceti, Cetacea). Journal of Experimental Biology 204(22): 3829-41. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Abstract: Hearing is attenuated in the aerial ear of humans and other land mammals tested in pressure chambers as a result of middle ear impedance changes that result from increased air density. We tested the hypothesis, based on recent middle ear models, that increasing the density of middle ear air at depth might attenuate whale hearing. Two white whales Delphinapterus leucas made dives to a platform at a depth of 5, 100, 200 or 300 m in the Pacific Ocean. During dives to station on the platform for up to 12 min, the whales whistled in response to 500 ms tones projected at random intervals to assess their hearing threshold at each depth. Analysis of response whistle spectra, whistle latency in response to tones and hearing thresholds showed that the increased hydrostatic pressure at depth changed each whale's whistle response at depth, but did not attenuate hearing overall. The finding that whale hearing is not attenuated at depth suggests that sound is conducted through the head tissues of the whale to the ear without requiring the usual ear drum/ossicular chain amplification of the aerial middle ear. These first ever hearing tests in the open ocean demonstrate that zones of audibility for human-made sounds are just as great throughout the depths to which these whales dive, or at least down to 300 m.
Descriptors: hearing, immersion, vocalization, animal, whales physiology, diving, ear anatomy and histology, ear physiology, hydrostatic pressure, Pacific Ocean, reaction time, whales anatomy and histology.
Ridgway, S.H. (2000). The auditory central nervous system of dolphins. In: W.W.L. Au, A.N. Popper and R.R. Fay Hearing by Whales and Dolphins, Springer Handbook of Auditory Research, p. 273-293. ISBN: 0387949062.
NAL Call Number: QL737.C432H43 2000
Descriptors: Tursiops truncatus, literature review, nervous system, functional morphology, review, brain, auditory, central nervous system, sound reception, echolocation.
Rimskaya Korsakova, L.K. and N.A. Dubrovskii (2003). Interaural time and level differences in the auditory analysis of ultrasonic pulses at dolphins: Simulation experiments. Sensornye Sistemy 17(1): 68-80. ISSN: 0235-0092.
Descriptors: Sotalia fluviatilis, ear, ultrasonic pulse analysis, interaural time and level differences, role in echolocation, echolocation, acoustic signals, sound, ultrasonic pulses.
Roitblat, H.L. (2003). Object recognition by dolphins. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 278-283. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Odontoceti, echolocation, object recognition, computation theory.
Saprykin, V.A., S.V. Kovtunenko, V.P. Korolev, E.S. Dmitrieva, V.I. Ol'shanskii, and I.V. Bekker (1977). Invariability of auditory perception with respect to frequency--time signal transformations in the dolphin Tursiops truncatus. Neuroscience and Behavioral Physiology 8(4): 330-3. ISSN: 0097-0549.
NAL Call Number: QP351.N4
Abstract: The characteristic of hearing in the dolphin Tursiops truncatus were investigated by the method of motor-feeding conditioned reflexes under conditions of frequency--time signal indeterminancy with background noise. It was shown that the effectiveness of auditory detection of tone--pulse signals is invariant with respect to Doppler and shift signal transformations, while the number of waves is a characteristic parameter of the auditory system.
Descriptors: auditory perception physiology, dolphins physiology, discrimination psychology physiology.
Schlundt, C.E., D.A. Carder and S.H. Ridgway (2003). The effect of projector position on the underwater hearing thresholds of bottlenose dolphins (Tursiops truncatus) at 2, 8 and 12 kHz. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 109-114. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Tursiops truncatus, sound reception, underwater hearing, thresholds, effect of projector position.
Schotten, M., W.W.L. Au, M.O. Lammers and R. Aubauer (2003). Echolocation recordings and localization of wild spinner dolphins (Stenella longirostris) and pantropical spotted dolphins (S. attenuata) using a four-hydrophone array. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 393-400. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Stenella attenuata, Stenella longirostris, observation techniques, sound recording techniques, echolocation clicks localization and recording using hydrophones array, echolocation, north Pacific, Hawaii, Oahu, echolocation clicks localization and recording method.
Schultz, K.W., D.H. Cato, P.J. Corkeron, and M.M. Bryden (1995). Low frequency narrow-band sounds produced by bottlenose dolphins. Marine Mammal Science 11(4): 503-509. ISSN: 0824-0469.
NAL Call Number: QL713.2.M372
Abstract: We present a new sound type recorded from bottlenose dolphins, Tursiops truncatus, in eastern Australian waters: low-frequency, narrow-band (LFN) harmonic sounds (defined as less than 2 kHz). Most of these sounds were of frequencies less than 1 kHz and were recorded commonly from socializing dolphins. These sounds differ significantly from narrow-band whistles, which are higher in frequency and longer in duration. The absence of these sounds in most studies of the acoustic behavior of bottlenose dolphins may reflect geographic differences in repertoires or result from insufficient sampling. Alternatively, these sounds may have been ignored where the focus of research was on other sound types.
Descriptors: behavior, communication, marine ecology, ecology, environmental sciences, systematics and taxonomy.
Shimada, H. (2002). Acoustic techniques for assessment of large cetaceans. Aquabiology (Tokyo) 24(1): 63-66; 138. ISSN: 0285-4376.
NAL Call Number: QH90.A1K35
Descriptors: Cetacea, techniques, acoustic techniques, use in assessment of large taxa.
Sirovic, A., J.A. Hildebrand, S.M. Wiggins, M.A. McDonald, S.E. Moore, and D. Thiele (2004). Seasonality of blue and fin whale calls and the influence of sea ice in the western Antarctic Peninsula. Deep Sea Research. Part II. Topical Studies in Oceanography 51(17-19): 2327-2344. ISSN: 0967-0645.
Abstract: The calling seasonality of blue (Balaenoptera musculus) and fin (B. physalus) whales was assessed using acoustic data recorded on seven autonomous acoustic recording packages (ARPs) deployed from March 2001 to February 2003 in the Western Antarctic Peninsula. Automatic detection and acoustic power analysis methods were used for determining presence and absence of whale calls. Blue whale calls were detected year round, on average 177 days per year, with peak calling in March and April, and a secondary peak in October and November. Lowest calling rates occurred between June and September, and in December. Fin whale calling rates were seasonal with calls detected between February and June (on average 51 days/year), and peak calling in May. Sea ice formed a month later and retreated a month earlier in 2001 than in 2002 over all recording sites. During the entire deployment period, detected calls of both species of whales showed negative correlation with sea ice concentrations at all sites, suggesting an absence of blue and fin whales in areas covered with sea ice. A conservative density estimate of calling whales from the acoustic data yields 0.43 calling blue whales per 1000 n mi2 and 1.30 calling fin whales per 1000 n mi2, which is about one-third higher than the density of blue whales and approximately equal to the density of fin whales estimated from the visual surveys. (C) 2004 Elsevier Ltd. All rights reserved.
Descriptors: Balaenoptera musculus, Balaenoptera physalus, acoustic signals, population density, climate and weather, sea ice, Antarctic Ocean, Antarctica, western Antarctic Peninsula, calling variation, seasonality and influence of sea ice.
Steiner, W.W., J.H. Hain, H.E. Winn, and P.J. Perkins (1979). Vocalizations and feeding behavior of the killer whale (Orcinus orca). Journal of Mammalogy 60(4): 823-827. ISSN: 0022-2372.
NAL Call Number: 410 J823
Descriptors: Orcinus orca, feeding behavior, cooperative behavior, observations, behavior, vocalizations, sonograms, group behavior, cooperative feeding behavior, Newfoundland, north west Atlantic, vocalizations.
Supin, A.Y., P.E. Nachtigall, W.W. Au, and M. Breese (2004). The interaction of outgoing echolocation pulses and echoes in the false killer whale's auditory system: evoked-potential study. Journal of the Acoustical Society of America 115(6): 3218-25. ISSN: 0001-4966.
Abstract: Brain auditory evoked potentials (AEP) associated with echolocation were recorded in a false killer whale Pseudorca crassidens trained to accept suction-cup EEG electrodes and to detect targets by echolocation. AEP collection was triggered by echolocation pulses transmitted by the animal. The target was a hollow aluminum cylinder of strength of -22 dB at a distance from 1 to 8 m. Each AEP record was obtained by averaging more than 1000 individual records. All the records contained two AEP sets: the first one of a constant latency and a second one with a delay proportional to the distance. The timing of these two AEP sets was interpreted as responses to the transmitted echolocation pulse and echo, respectively. The echo-related AEP, although slightly smaller, was comparable to the outgoing click-related AEP in amplitude, even though at a target distance as far as 8 m the echo intensity was as low as -64 dB relative to the transmitted pulse in front of the head. The amplitude of the echo-related AEP was almost independent of distance, even though variation of target distance from 1 to 8 m influenced the echo intensity by as much as 36 dB.
Descriptors: dolphins physiology, echolocation physiology, evoked potentials, auditory physiology, acoustic stimulation, audiometry, evoked response methods, discrimination learning physiology, form perception physiology.
Supin, A.Y., V.V. Popov, and V.O. Klishin (1993). ABR frequency tuning curves in dolphins. Journal of Comparative Physiology. A, Sensory, Neural, and Behavioral Physiology 173(5): 649-56. ISSN: 0340-7594.
NAL Call Number: QP33.J68
Abstract: Tone-tone masking was used to determine auditory brain-stem response tuning curves in dolphins (Tursiops truncatus) in a simultaneous-masking paradigm. The Q10 of the curves was as large as 16-19 in the frequency range 64-128 kHz. In the range 45-16 kHz, Q10 decreased proportionally to the frequency with the bandwidth of the curves being constant, about 3.5-4 kHz at the 10-dB level. Tuning curves below 45 kHz are supposed to reflect broad spectral bandwidth of the probe's effective part which is no longer than 0.5 ms, irrespective of actual probe duration. Tuning curves above 64 kHz are supposed to reflect the real frequency tuning of the dolphin's auditory system.
Descriptors: auditory perception physiology, brain stem physiology, dolphins physiology, acoustic stimulation, perceptual masking.
Supin, A.Y. (1994). Auditory mechanisms in dolphins. Sensornye Sistemy 8(3-4): 204-212. ISSN: 0235-0092.
Descriptors: nervous system, neural coordination, sense organs, sensory reception, sound conductance, sound source direction sensitivity, temporal hearing resolution.
Supin, A.Y. and V. Popov (2000). Frequency-modulation sensitivity in bottlenose dolphins, Tursiops truncatus: evoked-potential study. Aquatic Mammals 26(1): 83-94. ISSN: 0167-5427.
Descriptors: Tursiops truncatus, echolocation, frequency modulation sensitivity, evoked potential study.
Supin, A.Y. and V.V. Popov (2003). Temporal processing of rapidly following sounds in dolphins: evoked-potential study. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 153-161. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Tursiops truncatus, brain, auditory brainstem, temporal processing of auditory stimuli, echolocation.
Szymanski, M.D., D.E. Bain, K. Kiehl, S. Pennington, S. Wong, and K.R. Henry (1999). Killer whale (Orcinus orca) hearing: auditory brainstem response and behavioral audiograms. Journal of the Acoustical Society of America 106(2): 1134-41. ISSN: 0001-4966.
Abstract: Killer whale (Orcinus orca) audiograms were measured using behavioral responses and auditory evoked potentials (AEPs) from two trained adult females. The mean auditory brainstem response (ABR) audiogram to tones between 1 and 100 kHz was 12 dB (re 1 mu Pa) less sensitive than behavioral audiograms from the same individuals (+/- 8 dB). The ABR and behavioral audiogram curves had shapes that were generally consistent and had the best threshold agreement (5 dB) in the most sensitive range 18-42 kHz, and the least (22 dB) at higher frequencies 60-100 kHz. The most sensitive frequency in the mean Orcinus audiogram was 20 kHz (36 dB), a frequency lower than many other odontocetes, but one that matches peak spectral energy reported for wild killer whale echolocation clicks. A previously reported audiogram of a male Orcinus had greatest sensitivity in this range (15 kHz, approximately 35 dB). Both whales reliably responded to 100-kHz tones (95 dB), and one whale to a 120-kHz tone, a variation from an earlier reported high-frequency limit of 32 kHz for a male Orcinus. Despite smaller amplitude ABRs than smaller delphinids, the results demonstrated that ABR audiometry can provide a useful suprathreshold estimate of hearing range in toothed whales.
Descriptors: audiometry methods, behavior, animal physiology, dolphins physiology, evoked potentials, auditory, brain stem physiology, hearing physiology, auditory threshold physiology.
Takemura, A. and M. Nishiwaki (1975). Studies on the underwater sound, 5: On the underwater calls of the Indus River dolphin (Platanista gangetica). Bulletin of the Faculty of Fisheries Nagasaki University (40): 1-6.
Descriptors: under water sounds, studies, calls, Indus River dolphin, Platanista gangetica.
Language of Text: English summary.
Tavolga, W.N. (1983). Theoretical principles for the study of communication in cetaceans [animal communication, social behaviour]. Mammalia 47(1): 3-26. ISSN: 0025-1461.
NAL Call Number: 410 M31
Descriptors: communication, cetaceans, principles, theoretical, social behavior, study.
Language of Text: French and English summaries.
Teilmann, J., L.A. Miller, T. Kirketerp, R.A. Kastelein, P.T. Madsen, B.K. Nielsen, and W.W.L. Au (2002). Characteristics of echolocation signals used by a harbour porpoise (Phocoena phocoena) in a target detection experiment. Aquatic Mammals 28(3): 275-284. ISSN: 0167-5427.
Descriptors: Phocoena phocoena, echolocation, signal characteristics, target detection.
Thewissen, J.G. and S.T. Hussain (1993). Origin of underwater hearing in whales. Nature (London) 361(6411): 444-5. ISSN: 0028-0836.
NAL Call Number: 472 N21
Abstract: All described fossil and Recent cetaceans have relatively similar ear bones (malleus, incus and stapes) that strongly diverge from those of land mammals. Here we report that the hearing organ of the oldest whale, Pakicetus, is the only known intermediate between that of land mammals and aquatic cetaceans (whales, dolphins and porpoises). The incus of Pakicetus is intermediate with respect to inflation, crural proportions, and position of the mallear joint. The incus and mandible of Pakicetus indicate that the path of soundwaves to its ear resembled that of land mammals. These fossils suggest that the first whale was amphibious, and corroborate the hypothesis that artiodactyls (for example, pigs, camels and ruminants) are the closest extant relatives of cetaceans.
Descriptors: evolution, fossils, hearing physiology, whales anatomy and histology, whales physiology, ear anatomy and histology, ear physiology, jaw anatomy and histology, jaw physiology.
Thode, A. (2004). Tracking sperm whale (Physeter macrocephalus) dive profiles using a towed passive acoustic array. Journal of the Acoustical Society of America 116(1): 245-53. ISSN: 0001-4966.
Abstract: A passive acoustic method is presented for tracking sperm whale dive profiles, using two or three hydrophones deployed as either a vertical or large-aperture towed array. The relative arrival times between the direct and surface-reflected acoustic paths are used to obtain the ranges and depths of animals with respect to the array, provided that the hydrophone depths are independently measured. Besides reducing the number of hydrophones required, exploiting surface reflections simplifies automation of the data processing. Experimental results are shown from 2002 and 2003 cruises in the Gulf of Mexico for two different towed array deployments. The 2002 deployment consisted of two short-aperture towed arrays separated by 170 m, while the 2003 deployment placed an autonomous acoustic recorder in tandem with a short-aperture towed array, and used ship noise to time-align the acoustic data. The resulting dive profiles were independently checked using single-hydrophone localizations, whenever multipath reflections from the ocean bottom could be exploited to effectively create a large-aperture vertical array. This technique may have applications for basic research and for real-time mitigation for seismic airgun surveys.
Descriptors: acoustics, diving, whales physiology, oceans and seas, sound, vocalization, animal physiology.
Thode, A., D.K. Mellinger, S. Stienessen, A. Martinez, and K. Mullin (2002). Depth-dependent acoustic features of diving sperm whales (Physeter macrocephalus) in the Gulf of Mexico. Journal of the Acoustical Society of America 112(1): 308-21. ISSN: 0001-4966.
Abstract: Three-dimensional dive trajectories of three sperm whales in the Gulf of Mexico have been obtained by measuring the relative arrival times and bearings of the animals' acoustic multipath reflections, using two elements of a towed hydrophone array deployed at an unknown depth and orientation. Within the first 6-12 min of the start of a dive, the intervals between successive "clicks" of all three whales corresponded closely with the two-way travel time of an acoustic pulse traveling vertically between the animals' position and the ocean bottom. The click spectra contained multiple peaks, including a faint band of energy originally centered near 10 kHz. As the animals descended over 500 m in depth, the center frequency of this band shifted to nearly 15 kHz, but subsequently remained near this value during the rest of the dive. This frequency shift is consistent with that expected from energy scattering from an ensemble of incompressible small-scale air-filled resonators, with diameters on the order of 4 mm. One possible candidate for such an ensemble is proposed to reside in the collapsed frontal sac of the animal. A comparison of the received levels for the bottom and direct multipath arrivals indicates that the whales' acoustic directivity must range between 10-30 dB in the 5-20-kHz region.
Descriptors: acoustics, diving, echolocation, models, biological, oceans and seas, whales.
Thomas, J.A., C.F. Moss and M. Vater (Editors) (2003). Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, 604 p. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Odontoceti, Chiroptera, comprehensive works, echolocation, collected papers.
Thomas, R.E., K.M. Fristrup, and P.L. Tyack (2002). Linking the sounds of dolphins to their locations and behavior using video and multichannel acoustic recordings. Journal of the Acoustical Society of America 112(4): 1692-701. ISSN: 0001-4966.
Abstract: It is difficult to attribute underwater animal sounds to the individuals producing them. This paper presents a system developed to solve this problem for dolphins by linking acoustic locations of the sounds of captive bottlenose dolphins with an overhead video image. A time-delay beamforming algorithm localized dolphin sounds obtained from an array of hydrophones dispersed around a lagoon. The localized positions of vocalizing dolphins were projected onto video images. The performance of the system was measured for artificial calibration signals as well as for dolphin sounds. The performance of the system for calibration signals was analyzed in terms of acoustic localization error, video projection error, and combined acoustic localization and video error. The 95% confidence bounds for these were 1.5, 2.1, and 2.1 m, respectively. Performance of the system was analyzed for three types of dolphin sounds: echolocation clicks, whistles, and burst-pulsed sounds. The mean errors for these were 0.8, 1.3, and 1.3 m, respectively. The 95% confidence bound for all vocalizations was 2.8 m, roughly the length of an adult bottlenose dolphin. This system represents a significant advance for studying the function of vocalizations of marine animals in relation to their context, as the sounds can be identified to the vocalizing dolphin and linked to its concurrent behavior.
Descriptors: behavior, animal physiology, sound localization physiology, videotape recording, vocalization, animal physiology, acoustics, dolphins.
Thompson, P.O., W.C. Cummings, and S.J. Ha (1986). Sounds, source levels, and associated behavior of humpback whales, southeast Alaska. Journal of the Acoustical Society of America 80(3): 735-40. ISSN: 0001-4966.
NAL Call Number: QC221.A27
Abstract: Humpback whales in Southeast Alaskan waters produced five categories of sounds: moans, grunts, pulse trains, blowhole-associated sounds, and surface impacts. Frequencies (Hz) of moans and grunts were 20-1900. Major energy in low-frequency pulse trains was in a band of 25-80 Hz with pulse duration of 300-400 ms. Blowhole-associated sounds, recorded as transiting whales encountered one another, were of two types: shrieks, 555-2000 Hz, and trumpetlike horn blasts with fundamental at 414 Hz (median). Pulses and spread spectrum noise were associated with gas bubble formation and explosive bursts, respectively, in connection with spiral feeding maneuvers. Surface impacts resulted from fluke or flipper slaps in sequences of 3-21 sounds. Source levels ranged from 162 (low-frequency pulse trains) to 192 dB (surface impacts), re: 1 microPa, 1 m. Songs, commonly heard on winter breeding grounds, were absent from our recordings. Feeding and perhaps certain other whale activities can be monitored based on sound production.
Descriptors: Cetacea physiology, vocalization, animal, whales physiology, Pacific Ocean, sound spectrography methods.
Thomsen, F., D. Franck, and J.K. Ford (2002). On the communicative significance of whistles in wild killer whales (Orcinus orca). Naturwissenschaften 89(9): 404-7. ISSN: 0028-1042.
NAL Call Number: 474 N213
Abstract: Killer whales (Orcinus orca) use pulsed calls and whistles in underwater communication. Unlike pulsed calls, whistles have received little study and thus their function is poorly known. In this study, whistle activities of groups of individually known killer whales were compared quantitatively across behavioural categories. Acoustic recordings and simultaneous behavioural observations were made of northern resident killer whales off Vancouver Island in 1996 and 1997. Whistles were produced at greater rates than discrete calls during close-range behavioural activities than during long-range activities. They were the predominant sound-type recorded during socializing. The number of whistles per animal per minute was significantly higher during close-range behavioural activities than during long-range activities. Evidently, whistles play an important role in the close-range acoustic communication in northern resident killer whales.
Descriptors: dolphins physiology, vocalization, animal, animals, wild, British Columbia, feeding behavior, motor activity, Pacific Islands, social behavior.
Tromans, A. (2003). Volume control. Nature (London) 423(6942): 815. ISSN: 0028-0836.
NAL Call Number: 472 N21
Descriptors: acoustics, dolphins physiology, echolocation physiology, sound, Chiroptera physiology.
Notes: Comment On: Nature. 2003 Jun 19;423(6942):861-3.
Turl, C.W. (1993). Low-frequency sound detection by a bottlenose dolphin. Journal of the Acoustical Society of America 94(5): 3006-8. ISSN: 0001-4966.
Descriptors: dolphins, echolocation, sound localization, acoustics, auditory perception, auditory threshold, behavior, animal, hearing, noise.
Tyack, P.L. (2000). Animal behavior. Dolphins whistle a signature tune. Science 289(5483): 1310-1. ISSN: 0036-8075.
NAL Call Number: 470 Sci2
Descriptors: dolphins physiology, imitative behavior, learning, social behavior, vocalization, animal, animals, wild physiology, brain anatomy and histology, brain physiology, evolution, intelligence.
Notes: Comment On: Science. 2000 Aug 25;289(5483):1355-7.
Tyack, P.L. (2003). Dolphins communicate about individual-specific social relationships. In: F.B.M. de Waal and P.L. Tyack (Editors), Animal Social Complexity: Intelligence, Culture, and Individualized Societies, Harvard University Press: Cambridge & London, p. 342-361. ISBN: 0674009290.
Descriptors: Delphinidae, literature review, acoustic signals, vocalizations, social communication, review, social behavior.
Tyack, P.L. (2000). Functional aspects of cetacean communication. In: J. Mann, R.C. Connor, P.L. Tyack and H. Whitehead (Editors), Cetacean Societies: Field Studies of Dolphins and Whales, Chicago University Press: Chicago & London, p. 270-307. ISBN: 0226503410.
NAL Call Number: QL737.C4C39 2000
Descriptors: Cetacea, literature review, communication, functional aspects, review.
Tyack, P.L. and C.W. Clark (2000). Communication and acoustic behavior of dolphins and whales. In: W.W.L. Au, A.N. Popper and R.R. Fay (Editors), Hearing by Whales and Dolphins, Springer Handbook of Auditory Research, p. 156-224. ISBN: 0387949062.
NAL Call Number: QL737.C432H43 2000
Descriptors: Cetacea, literature review, evolutionary adaptation, acoustic adaptations, natural selection, behavioral variation, acoustic signals, vocalization structure and function, review.
Van Opzeeland, I.C., P.J. Corkeron, T. Leyssen, T. Simila, and S.M. Van Parijs (2005). Acoustic behaviour of Norwegian killer whales, Orcinus orca, during carousel and seiner foraging on spring-spawning herring. Aquatic Mammals 31(1): 110-119. ISSN: 0167-5427.
Abstract: Norwegian killer whales (Orcinus orca) use different techniques to forage on spring-spawning herring. Two of the commonly observed techniques are carousel feeding, a cooperative feeding method, and seiner feeding, a noncooperative method. During seiner foraging, large groups of whales forage on herring discards around the nets or on discarded by-catch of fishing boats. This study was to examine possible differences in killer whale acoustic behaviour during both foraging contexts using simple sound analysis techniques. Calling, echolocation, and tail-slap activities were measured and compared between foraging contexts. The study suggest that the sequence of call types, rather than the use of isolated call types, is of greater importance in the coordination of group movements during carousel foraging.
Descriptors: behavior, marine ecology, ecology, simple sound analysis, applied and field techniques, fishing boat, field equipment, echolocation, foraging, group movement, seiner foraging, carousel foraging.
Van Parijs, S.M., T. Leyssen, and T. Simila (2004). Sounds produced by Norwegian killer whales, Orcinus orca, during capture. Journal of the Acoustical Society of America 116(1): 557-60. ISSN: 0001-4966.
Abstract: To date very little is still known about the acoustic behavior of Norwegian killer whales, in particular that of individual whales. In this study a unique opportunity was presented to document the sounds produced by five captured killer whales in the Vestfjord area, northern Norway. Individuals produced 14 discrete and 7 compound calls. Two call types were used both by individuals 16178 and 23365 suggesting that they may belong to the same pod. Comparisons with calls documented in Strager (1993) showed that none of the call types used by the captured individuals were present. The lack of these calls in the available literature suggests that call variability within individuals is likely to be large. This short note adds to our knowledge of the vocal repertoire of this population and demonstrates the need for further studies to provide behavioural context to these sounds.
Descriptors: dolphins physiology, vocalization, animal, acoustics, behavior, animal, Norway, sound spectrography.
Van Parijs, S.M., G.J. Parra, and P.J. Corkeron (2000). Sounds produced by Australian Irrawaddy dolphins, Orcaella brevirostris. Journal of the Acoustical Society of America 108(4): 1938-40. ISSN: 0001-4966.
Abstract: Sounds produced by Irrawaddy dolphins, Orcaella brevirostris, were recorded in coastal waters off northern Australia. They exhibit a varied repertoire, consisting of broadband clicks, pulsed sounds and whistles. Broad-band clicks, "creaks" and "buzz" sounds were recorded during foraging, while "squeaks" were recorded only during socializing. Both whistle types were recorded during foraging and socializing. The sounds produced by Irrawaddy dolphins do not resemble those of their nearest taxonomic relative, the killer whale, Orcinus orca. Pulsed sounds appear to resemble those produced by Sotalia and nonwhistling delphinids (e.g., Cephalorhynchus spp.). Irrawaddy dolphins exhibit a vocal repertoire that could reflect the acoustic specialization of this species to its environment.
Descriptors: animal communication, dolphins, vocalization, animal, Queensland, sound spectrography, species specificity.
Van Parijs, S.M. and P.J. Corkeron (2001). Vocalizations and behaviour of Pacific humpback dolphins Sousa chinensis. Ethology 107(8): 701-716. ISSN: 0179-1613.
NAL Call Number: QL750.E74
Descriptors: Sousa chinensis, behavior, acoustic signals, vocalizations characteristics, behavior relations, west Pacific, Australia, Queensland, Stradbroke Island, vocalizations characteristics relations.
Van Parijs, S.M., C. Lydersen, and K.M. Kovacs (2003). Sounds produced by individual white whales, Delphinapterus leucas, from Svalbard during capture (L.). Journal of the Acoustical Society of America 113(1): 57-60. ISSN: 0001-4966.
Descriptors: Delphinapterus leucas, behavioral variation, acoustic signals, Arctic Ocean, Svalbard, Storfjorden, sounds produced during capture.
Varanasi, U., H.R. Feldman, and D.C. Malins (1975). Molecular basis for formation of lipid sound lens in echolocating Cetaceans. Nature (London) 255(5506): 340-343.
NAL Call Number: 472 N21
Descriptors: echolocating, cetaceans, lipid sound lens, molecular basis, formation.
Vater, M. and M. Koessl (2003). The ears of whales and bats. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 89-99. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Odontoceti, Chiroptera, ear, cochlea and sound conducting apparatus, anatomy and function, echolocation, evolutionary adaptation.
Verboom, W.C. and R.A. Kastelein (2003). Structure of harbor porpoise (Phocoena phocoena) acoustic signals with high repetition rates. In: J.A. Thomas, C.F. Moss and M. Vater (Editors), Echolocation in Bats and Dolphins, University of Chicago Press: Chicago & London, p. 40-43. ISBN: 0226795993.
NAL Call Number: QL737.C5E28 2004
Descriptors: Phocoena phocoena, echolocation, structure of acoustic signals with high repetition rates.
Wahlberg, M. (2002). The acoustic behaviour of diving sperm whales observed with a hydrophone array. Journal of Experimental Marine Biology and Ecology 281(1-2): 53-62. ISSN: 0022-0981.
NAL Call Number: QH91.A1J6
Descriptors: behavior, acoustic behavior, bottom depth, click sequences, diving, echolocation, sound production, sperm whales, hydrophone, prey.
Watkins, W.A. (1981). Activities and underwater sounds of fin whales [Balaenoptera physalus]. Scientific Reports of the Whales Research Institute (33): 83-117. ISSN: 0083-9086.
Descriptors: whales, Balaenopterus, sound, sea water, vibration, acoustic properties, movement, animals, aquatic animals, aquatic mammals, aquatic organisms, Cetacea, chemicophysical properties, ergonomic factors, ISSCAAP group b 61, ISSCAAP group b 62, ISSCAAP groups of species, mammals, meat animals, oil producing animals, physics, physiological functions, physiology, vertebrates, water.
Language of Text: English summary.
Watkins, W.A., M.A. Daher, J.E. George, and D. Rodriguez (2004). Twelve years of tracking 52-Hz whale calls from a unique source in the North Pacific. Deep Sea Research. Part A. Oceanographic Research Papers 51(12): 1889-1901. ISSN: 0967-0637.
Descriptors: Cetacea, acoustic signals, north Pacific, underwater calls, acoustic tracking.
Watwood, S.L., P.L. Tyack, and R.S. Wells (2004). Whistle sharing in paired male bottlenose dolphins, Tursiops truncatus. Behavioral Ecology and Sociobiology 55(6): 531-543. ISSN: 0340-5443.
NAL Call Number: QL751.B4
Abstract: The signature whistle hypothesis states that dolphins produce highly stereotyped, individually distinctive whistles when in isolation. The presence of signature whistles has been called into question by recent studies proposing that dolphins produce a shared, simple upsweep whistle when in isolation, and that whistles produced by socializing dolphins are shared across individuals and social groups. This shared repertoire hypothesis suggests that when two animals produce the same whistle type, it is due to sharing the same common repertoire rather than one animal learning to produce the whistle of another. One difference between studies supporting or denying the existence of signature whistles is the method used to classify whistle types. We examined whistle production by 17 free-ranging bottlenose dolphins while temporarily restrained. We used both a quantitative comparison technique similar to that used to support the shared repertoire hypothesis and human judges to classify whistle types and quantify similarity between types. Contrary to recent studies that emphasize shared whistles, overall whistle sharing between isolated individuals was low (25%) and a simple upsweep did not account for the most common whistle type in half of the animals. Some species of birds, bats, and primates with stable social groups use vocal learning to converge over time to one common group distinctive call type. We examined whistle similarity between adult male dolphins that are partners in a close social alliance in order to test whether vocal learning may enable a similar vocal convergence. Whistle similarity was rated very high between partners and low between non-partners by both the quantitative technique and human observers. This suggests that as in songbirds and some other mammals, adult male bottlenose dolphins may use vocal learning to converge on similar whistles as they develop affiliative social relationships.
Descriptors: Tursiops truncatus, acoustic signals, signature whistles, characteristics and evidence for whistle sharing, Gulf of Mexico, USA, Florida, Sarasota Bay, signature whistle characteristics and evidence for whistle sharing, adult males.
Wisdom, S., A.E. Bowles, and K.E. Anderson (2001). Development of behavior and sound repertoire of a rehabilitating gray whale calf. Aquatic Mammals 27(3): 239-255. ISSN: 0167-5427.
Descriptors: Eschrichtius robustus, gray whale, young, development, rehabilitating, acoustic signals, behavior in captivity, behavior, sound, repertoire.
Zaitseva, K.A. and V.I. Korolev (2000). Mekhanizmy izmereniia sonarom del'fina Tursiops trancatus skorosti i uskoreniia gidrolokatsionnoi tseli. [Mechanism of the sonar detection of the echolocation target speed and acceleration by the dolphin Tursiops truncatus]. Zhurnal Evoliutsionnoi Biokhimii i Fiziologii 36(2): 136-40. ISSN: 0044-4529.
Descriptors: dolphins physiology, echolocation physiology, conditioning, classical, sound spectrography.
Language of Text: Russian.
Zaslavskiy, G. (2001). Temporal order discrimination in the dolphin. Proceedings of the Institute of Acoustics 23(4): 143-151. ISSN: 0309-8117.
Descriptors: Tursiops truncatus, echolocation, temporal order discrimination.
Zaslavskiy, G. and V. Ryabov (2001). Target classification in the dolphin. Proceedings of the Institute of Acoustics 23(4): 75-78. ISSN: 0309-8117.
Descriptors: Tursiops truncatus, echolocation, target classification.
Zaslavskiy, G.L. (2001). Click discrimination in the dolphin. Proceedings of the Institute of Acoustics 23(4): 93-99. ISSN: 0309-8117.
Descriptors: Tursiops truncatus, echolocation, click discrimination.