U. S. Department of Labor
Occupational Safety and Health Administration
Directorate of Science, Technology and Medicine
Office of Science and Technology Assessment
Hearing Conservation for the Hearing-Impaired
Worker
Safety and Health Information Bulletin
SHIB 12-27-2005
This Safety and Health Information Bulletin is not a standard or regulation, and
it creates no new legal obligations. The Bulletin is advisory in nature,
informational in content, and is intended to assist employers in providing a
safe and healthful workplace. Pursuant to the Occupational Safety and Health Act,
employers must comply with hazard-specific safety and health standards
promulgated by OSHA or by a state with an OSHA-approved state plan. In addition,
pursuant to Section 5(a)(1), the General Duty Clause of the Act, employers must
provide their employees with a workplace free from recognized hazards likely to
cause death or serious physical harm. Employers can be cited for violating the
General Duty Clause if there is a recognized hazard and they do not take
reasonable steps to prevent or abate the hazard. However, failure to implement
any recommendations in this Safety and Health Information Bulletin is not, in
itself, a violation of the General Duty Clause. Citations can only be based on
standards, regulations, and the General Duty Clause.
Introduction
Hearing-impaired workers face many challenges in the workplace, including communication, identifying and
using suitable hearing protection and the use of hearing aids at work. Industrial hearing
conservation programs may not fully address the specific needs of hearing-impaired workers for hearing protection
and communication. This Safety and Health Information Bulletin (SHIB) focuses on how hearing
conservation programs can address the needs of hearing-impaired workers who are exposed to high levels of noise
in their workplace. For additional information on workplace accommodations for hearing-impaired
workers for emergency preparedness/response and workplace safety in general, please refer to "Innovative Workplace Safety Accommodations for Hearing-Impaired
Workers," SHIB 07-22-2005.
Purpose
The purpose of this SHIB is to raise awareness about issues associated with protecting hearing-impaired
workers in noisy environments and to provide employers, workers and professional
organizations guidance on accommodating hearing-impaired individuals in the workplace when exposed to
high levels of noise. Specifically, this SHIB:
Informs employers that specialized hearing protectors are available that may benefit
occupationally exposed hearing-impaired workers in a variety of noisy workplaces;
Encourages employers to work as a team with hearing-impaired workers and the professional
in charge of the hearing conservation program to determine the appropriate hearing protection
for the hearing-impaired employee, and to determine on a case-by-case basis whether the worker’s
hearing aid can be appropriately worn in a noisy workplace under an earmuff;
Informs employers and hearing-impaired workers that individualized audiometric testing
protocols may be necessary to obtain valid audiograms.
Raises awareness about the need to protect the residual hearing of workers with hearing loss.
Hearing Conservation Issues Relating to Hearing-Impaired Workers
Use of Hearing Protection
OSHA’s occupational noise exposure standard includes requirements for hearing protection as part of the
employer’s hearing conservation program (29 CFR 1910.95(i)). It requires employers to make hearing protectors
available to all employees exposed to an 8-hour time-weighted average (TWA) sound level of 85 decibels (dBA) or greater. It also requires that hearing protectors be worn by employees exposed to an 8-hour TWA of 85 dBA if they have experienced a standard threshold shift (STS). Hearing protectors are also required to be used prior to receiving a baseline audiogram, and as required by 29 CFR 1910.95(b)(1). Employees must be given the opportunity to select their hearing protectors from a variety of suitable hearing protectors provided by the employer. The employer must ensure proper initial fitting and supervise the correct use of all hearing protectors. The employer must also evaluate the protector’s attenuation for the specific noise environments in which the protector will be used.
The use of hearing protection in the workplace is of special concern to workers who already have hearing loss. Hearing-impaired workers can have difficulty hearing co-workers, verbal instructions, the sound of machinery, or they may lack the ability to identify the direction of a sound source. Hearing-impaired workers may experience difficulty in using hearing protectors because conventional hearing protectors may reduce the speech volume level below the person’s threshold of audibility, especially for the important middle to higher frequency consonant sounds
[3]. Manufacturers are continually designing and upgrading specialized hearing protectors for
industrial, military, law enforcement, and fire and rescue team use. These may also benefit occupationally exposed hearing-impaired workers in a variety of noisy workplaces. Some of these innovative protectors are suitable for the hearing-impaired worker because they provide better clarity for speech recognition and communication, while still providing adequate protection in noisy environments by keeping
the sound that reaches the ear at a safe level [1]. As manufacturers respond to the need, a number of affordable hearing protection options are emerging that allow hearing-impaired workers to function safely and effectively in noisy environments without the risk of further hearing loss
[2].
Although workers with hearing impairment have lost part of their hearing ability, OSHA 29 CFR 1910.95(c) provides for protection of their residual hearing ability. Even employees who have been diagnosed with severe or profound deafness may have some residual hearing that needs to be protected from additional loss. Therefore, OSHA has taken the position that the requirements for using hearing protection in accordance with 29 CFR 1910.95(b)(1) and 1910.95(i)(2) apply to deaf employees. The Agency has stated that
"there is no exception (for hearing protection) for employees who have
diminished capacity to hear or for employees who have been diagnosed as deaf."
OSHA Letter of Interpretation, Tekla A. Staley, August 3, 2004.
Specialized hearing protectors
Specialized hearing protectors include passive (no electronics or amplification), active (a power supply and electronics), or communication headsets.
Passive hearing protectors
Flat or uniform-attenuating hearing protectors use mechanical means to filter the sound and provide nearly equal attenuation across the audible frequency range. In general, the signal sounds more natural, clearer and less distorted than the sound from conventional hearing protectors which often provide greater attenuation in the higher frequencies. When properly fitted, passive hearing protectors can provide adequate protection and users can hear more clearly and thus feel less isolated on the job. Workers with high frequency hearing losses may find these beneficial
[3,4].
Active hearing protectors
"Level dependent" (also known as sound restoration) hearing protectors not only block sound but use electronic circuitry to transmit low-level sounds through the hearing protector. They amplify incoming sounds up to a specified sound level depending on the model and type of hearing protector. Above the specified level, the electronic input is automatically reduced so that the protector no longer provides amplification which could lead to overexposure.
An advantage of these protectors is that during quiet time and intermittent noise there is no need to remove the hearing protector to hear well
[3,4].
Earmuffs with communication features are also available. These devices are designed with wireless (FM or infrared) or wired technology for-one or two-way communication systems. The devices provide specialized electronic circuits to limit the incoming sounds so that the earphones themselves do not create sound levels that are hazardous to the wearer
[3,4].
In extremely high noise levels, dual hearing protection (such as an earplug under an earmuff) equipped with
electronic/communication features may permit clearer communication without sacrificing attenuation.
[3].
For more information on available hearing protectors, the National Institute for Occupational Safety and Health (NIOSH) has an online
compendium of hearing protection
devices. Additionally, the U.S. Department of Labor’s Office of Disability Employment Policy
Technical Assistance Program’s Job Accommodation Network (JAN) has a Searchable Online Accommodation
Resource (SOAR) feature that lists hearing protector manufacturers that have provided information to
that network. Neither OSHA nor JAN recommends or endorses any company’s products.
However, JAN has valuable information
on the availability of specific hearing protectors for use with the hearing-impaired population.
Many workers have strong preferences for a particular type of hearing protector because of comfort, fit, and
communication demands. Experience has shown that the effectiveness of hearing protection
is diminished if it is removed for even a short period of time [3,11].
Therefore, comfort, communication, and hearing protectors that
allow for necessary job-related hearing is key to their preventive effect and the actual protection received
[3]. The
right hearing protector is one that is consistently worn. The graph below depicts the relationship between effective
hearing protection attenuation and the amount of time hearing protection is worn.
[11]. For problems with accessibility in using figures and illustrations in this
document,
please contact the Directorate of Science, Technology and Medicine at (202) 693-2300.
Selecting and Fitting Hearing Protection Devices
29 CFR 1910.95(i)(3) states that "employees shall be given the opportunity to select their hearing protectors from a variety of suitable hearing protectors provided by the employer." The phrase
"suitable hearing protectors" has been interpreted to mean protectors that are comfortable to wear and that offer sufficient attenuation to prevent hearing loss.
OSHA Letter of Interpretation, Danny D. Anderson, September 30, 1983.
In general, "employers are advised to give workers a choice between at least
one type of earplug and one type of muff; . . . the number of different hearing
protectors required to constitute an adequate variety is simply the number
needed to supply each employee that requires a hearing protector a suitable
one."
OSHA Letter of Interpretation, G.A. Brown, October 17, 1983.
To motivate workers to consistently wear hearing protectors in noisy situations, employers should engage workers
in determining their individual hearing protector needs. An employer should also consider referring a worker with a
hearing impairment for a one-on-one consultation with a qualified hearing conservation professional to determine
the most suitable hearing protector for the particular working environment. Important considerations for selecting
the appropriate hearing protector include the worker’s hearing and noise exposure levels, job
assignment, job-related hearing requirements, communication requirements and environmental considerations.
The chosen hearing protector must provide the needed amount of attenuation specific to each worker’s noise
exposure situation. Over attenuation (blocking too much sound) can produce undesirable and unnecessary
interference with speech and warning signals [5].
More information on the selection of hearing protectors and OSHA’s requirements for a hearing conservation
program can be found on the OSHA website. The website will direct you to standards, letters of
interpretation, technical guidance documents and informational pamphlets. NIOSH also has a wide variety of
information on noise and hearing loss and has a dedicated website for Noise and Hearing Loss Prevention.
Hearing Aid Usage in Industry
Some hearing-impaired workers who wear hearing aids want to be able to continue to wear hearing aids in their
workplaces even when exposed to high levels
of noise. They feel that with the hearing aid they can communicate better with co-workers, are able to better localize sound, and can hear warning or equipment sounds. Hearing
aids, however, in addition to amplifying useful sounds also amplify unwanted background noise
[4]. As
demonstrated in both laboratory and site measurements, noise amplified by hearing aids may exceed the OSHA
8-hour permissible limit of 90 dBA [6,7].
Consequently, hearing aids should not be worn in areas with hazardous noise
[2,6,7]. However, on a
case-by-case basis, hearing aids can be worn underneath an earmuff [7,12]. The hearing conservation professional, overseeing the hearing conservation program should be consulted to evaluate and manage these situations on a
case-by-case basis to ensure no further change in hearing occurs.
Workers have suggested that they want to wear their hearing aids at work in the turned-off position in lieu of
using hearing protection since they are accustomed to their own earmolds, and the hearing aid is already in their ear. Hearing aids are not hearing protectors. Hearing aids turned off do not provide enough blockage of sound to act as hearing protection, but
may reduce the sound enough to prevent the worker from hearing warning signals or other essential sounds
[2]. OSHA has stated that employees with
"a diminished capacity to hear cannot satisfy the requirement to wear hearing
protection simply by turning off their hearing aids when working in a high noise
area. Hearing aids are not hearing protectors."
OSHA Letter of Interpretation, Tekla A. Staley, August 3, 2004.
Individual evaluation by a qualified occupational hearing conservation professional and following-up
with the employee at the worksite will ascertain the suitability of the hearing aid and/or hearing protector for that particular employee’s noise environment.
Audiometric Testing Requirements
For the purpose of determining whether an employee has a standard threshold shift (STS), the hearing-impaired employee must remove his/her hearing aid and be tested with the appropriate headphones and procedures
specified in the hearing conservation standard, 29 CFR 1910.95(h)(1)-(h)(5); audiometric test requirements.
Considerations for testing hearing-impaired employees may include switching from an
automatic testing technique (with a microprocessor audiometer) to a manual technique to obtain valid
thresholds. This may be necessary due to the degree of hearing loss or other confounding factors such as ringing in the ears. Also,
"employees with hearing aids
should keep the aids on during the audiometric test instructions", and, " hearing aids should, of course, be
removed after the instructions have been given" [5]. Some hearing-impaired workers may need to be referred for further evaluation and testing if a valid
audiogram can not be obtained on-site [5].
The correct approach to address these challenges will
depend on facts specific to each individual situation, and should be resolved by collaborative teamwork
involving the employer, the hearing-impaired employee
and the hearing conservation professional [6,7].
Conclusion
The recommendations provided in this bulletin offer
guidance on addressing the special needs of hearing-impaired workers to protect their hearing in high noise
environments.
The risk of miscommunication, injury, and other
challenges presented to the hearing-impaired
employee in the workplace can be minimized through
the implementation of certain practical steps. These
include but are not limited to:
awareness that hearing-impaired workers may have special needs to protect their hearing,
providing information,
soliciting input,
providing choices,
team collaboration to ascertain individual workplace needs, and
referral for further evaluation, as appropriate
References
Hearing Health, "Future for Workers?". Lee Hager, Fall 2003.
Workers' Compensation Board of British Columbia, WorkSafe, "Working with
Hearing Loss-- Hearing Impairment, Noise, and Job Safety/Performance", May
29, 2003.
The Noise Manual, Fifth Edition, Chapter 10, Hearing Protection Devices,
Elliott Berger, May 2000, AIHA, Fairfax, Va.
Encyclopedia of Acoustics, "Hearing Protection Devices", ISBN
0-471-80465-7, 1977 John Wiley & Sons, Inc., and the 2004 TeleWeb Virtual
Seminar Series, New Developments in Hearing Protection, with an Update on Ratings
and Specialized Types of HPDs, July 27, 2004, Elliott Berger.
Council for Accreditation in Occupational Hearing Conservation (CAOHC)
Manual, Chapters 7, The Audiometric Testing Program, Chapter 8, Understanding the
Audiogram and Follow-Up Procedures, and Chapter 10, Hearing Protectors.
Journal of Speech and Hearing Research, "Noise Exposure Associated with
Hearing Aid Use in Industry". Thomas Dolan and James Maurer. Volume 39,
251-260, April 1996.
Occupational Health and Safety, "Hearing Aids in Occupational Settings:
Safety and Management Issues". Thomas Dolan and James Maurer. October 2000.
EARLog #18, "Can Hearing Aids Provide Hearing Protection?" Elliott Berger, E-A-R, Indianapolis, Ind.
Responses to NHCA/OSHA Alliance Questionnaire on Application of Accommodations to hearing conservation practices.
For information on the effect of hearing protector removal during exposure,
visit Kevin Michael and Associates. The web address is http://www.michaelassociates.com
National Hearing Conservation Association, comments provided.
For information on innovations in technology and hearing conservation, you may
visit Hearing Products Report. The web address is
http://www.hearingproductsreport.com/departments.ASP?Dept=H050911.