Research Results
NIOSH Occupational Noise and Hearing
Survey (ONHS): Evaluation of the Risk of Noise-Induced Hearing Loss
in Male Industrial Workers
Data now available from the 1968 - 1972 NIOSH Occupational Noise
and Hearing Survey (ONHS): Evaluation of the Risk of Noise-Induced
Hearing Loss in Male Industrial Workers. NIOSH has completed
a series of published research papers that provide a detailed analysis
of noise and hearing data collected during 1968-72 as part of the
NIOSH Occupational Noise and Hearing Survey. The first NIOSH Criteria
Document (1972) presented risk estimates of noise-induced hearing
loss (NIHL) based on analysis of 1172 male workers who were highly
screened to exclude workers with various hearing loss risk factors.
NIOSH revised the criteria document in 1998 with an updated risk
assessment of these 1172 male workers (Prince et al., 1997). NIOSH
later expanded the number of workers in the screened database to
include 894 workers with other risk factors for hearing loss. The
analysis of the total unscreened ONHS database has been recently
published in two journal articles (Prince, 2002; Prince et al.,
2003). The analysis of total unscreened industrial workers found
that variability in background risk and distribution of various
risk factors for hearing loss may explain some of the diversity
in excess of noise-induced hearing loss.
The following are the raw data files in MS Excel for (a) the screened
population (used for NIOSH Criteria document risk assessment and
1997 Prince et al paper) and (b) the total unscreened population
analyzed and published in 2002-2003. Accompanying the data files,
download the documentation of the data variable files.
Download raw data files
and documentation
(File is downloadable in Zip format - 171 KB)
View
and download references
Noise Exposure Assessment and Abatement
Strategies at an Indoor Firing Range
Exposure to hazardous impulse noise is common during the firing
of weapons at indoor firing ranges. The aims of this study were
to characterize the impulse noise environment at a law enforcement
firing range; document the insufficiencies found at the range from
a health and safety standpoint; and provide noise abatement recommendations
to reduce the overall health hazard to the auditory system.
Kardous CA, Willson RD, Hayden CS, Szlapa P, Murphy WJ, Reeves
ER. (2003) Noise exposure assessment and abatement strategies
at an indoor firing range. Appl Occup Environ Hyg 18(8):629-636.
 PDF
2.4MB (12 pages)
Alternative Field Methods for
Measuring Hearing Protector Performance
This article compares three field methods for measuring hearing
protector performance with the accepted laboratory method. Hearing
protectors are evaluated by how much sound is attenuated at several
frequencies. A subject is asked to identify when noise is just audible
for two the cases: with and without hearing protection. The differences
are measured at several frequencies. The field methods included
a test using large headphones that enclosed the external ear, a
test using speakers in a small testing booth and a third method
based on loudness matching. None of the three methods was found
to be significantly different from the laboratory method, however,
the lack of precision in the loudness matching method proved to
be unacceptable for use in an industrial setting. The other field
methods demonstrated acceptable agreement with the laboratory method.
Franks JR, Murphy WJ, Harris DA, Johnson JL, Shaw PB. (2003).
Alternative Field Methods for Measuring Hearing Protector Performance.
American Industrial Hygiene Association Journal. 64:501-509.
PDF
117KB (9 pages)
Development of a new standard
laboratory protocol for estimation of the field attenuation of hearing
protection devices: Sample size necessary to provide acceptable
reproducibility
This article examines the variability of hearing protector measurements
conducted in two different studies. The first study compared four
laboratories, four protectors, two fitting protocols and 24 subjects
per laboratory. The second study compared two laboratories, two
protectors, two fitting protocols and a total of 51 subjects. The
analysis of the results estimated the variability within subjects,
between subjects and between laboratories. Appropriate combination
of the variances yielded estimates of the reproducibility and repeatability
that can be expected for both intra- and inter-laboratory comparisons.
In most cases, the reproducibility for real ear attenuation at threshold
measurements was poorest for the 8000 Hz frequency. The paper develops
formulae that can be used for estimating the precision of a set
of measurements and the necessary sample size to yield a given precision.
The results of the interlaboratory studies were used as the basic
guidelines for testing 10 subjects for earmuffs and 20 subjects
for earplugs in the ANSI S12.6-1997 American National Standard
Method for Measuring of the Real-ear Attenuation at Threshold for
Hearing Protectors.
Murphy WJ et al. (2003). Development of a new standard laboratory
protocol for estimation of the field attenuation of hearing protection
devices: Sample size necessary to provide acceptable reproducibility.
J. Acoust. Soc. Am.
115: 311-323
PDF 771KB
(12 pages)
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