This position statement is a policy of the American Speech-Language-Hearing Association (ASHA). The document was developed by the Ad Hoc Committee on Occupational and Environmental Hearing Conservation and adopted by the American Speech-Language-Hearing Association (ASHA) Legislative Council in December 1995. Members of the Ad Hoc Committee on Occupational and Environmental Hearing Conservation include Derek Dunn, Rena H. Glaser, Theresa Schulz (chair), Andrew Stewart, Maureen E. Thompson (ex officio), and Vickie Tuten. Lawrence Higdon, ASHA vice president for professional practices in audiology, served as monitoring vice president. This position statement supersedes the 1985 position statement, “The Audiologist's Role in Occupational Hearing Conservation” (LC 7-84).
In today's complex industrial society, noise exposure poses an increasingly serious threat to individuals' hearing. There are approximately 28 million people in the United States with impaired hearing. Nearly 10 million of these cases are associated with loud noise (ASHA, 1991). It is difficult to quantify the number of Americans exposed to hazardous noise levels during nonoccupational activities. Examples of such activities include shooting, auto races, woodworking, power tool use, listening to amplified music, and so forth. Unlike some occupational exposures, nonoccupational exposures are not controlled by any regulations or guidelines.
On March 8, 1983, the Occupational Safety and Health Administration (OSHA) issued the final Hearing Conservation Amendment to its Occupational Noise Exposure Regulation (29 CFR 1910.95; U.S. DOL, 1981b). OSHA estimated that implementation of the amendment will reduce the number of American workers with occupational hearing impairment from more than 1 million to 261,000 by the year 2020. Beyond the prevention of noise-induced hearing loss (NIHL), the amendment was intended to produce occupational hearing conservation programs (OHCPs) that may reduce the incidence of stress-related illnesses, such as hypertension and ulcers, in environments where occupational noise may be a contributing factor (29 CFR 1910.25; U.S. DOL, 1981a).
Unfortunately, many occupations are not covered under the OSHA amendment. The National Institute for Occupational Safety and Health (NIOSH) estimated that many of the additional 15–20 million workers employed in unregulated nonmanufacturing industries (in particular, those in construction, agriculture, service, and trade industries) are likewise exposed to potentially hazardous noise. Although the mining industry is covered by the Mine Safety and Health Administration (MSHA), its noise exposure regulation is essentially a nonspecific performance regulation.
The OSHA Hearing Conservation Amendment led to the development of programs in occupational hearing conservation, many with obvious benefit to workers and employers in many industries and to the military. For these OHCPs to be effective, the interaction of professional disciplines—such as audiology, occupational medicine, industrial hygiene, engineering, and safety—in the implementation of OHCPs is vital. Audiologists with a strong background in all aspects of audiometric monitoring and interpretation of audiograms, equipment calibration, hearing conservation and rehabilitation, and noise measurement, can offer appropriate guidance and leadership in the development of OHCPs.
According to the 1994 ASHA Omnibus Survey, 45% of audiologists provide occupational hearing conservation (OHC) services (ASHA, 1994). The delivery of quality hearing conservation services by audiologists involved in these activities depends on proper academic preparation, professional experience, and adherence to standards of professional conduct.
This statement expresses ASHA's position regarding audiologists' participation in hearing conservation, both occupational and nonoccupational. For the purpose of this discussion, occupational hearing conservation is defined as the prevention of significant, permanent hearing loss resulting from on-the-job exposure to ototraumatic agents (of which noise is the most common). Nonoccupational hearing conservation refers to the prevention of significant, permanent hearing loss resulting from off-the-job exposure to ototraumatic agents (most commonly noise).
This statement has been formulated to offer guidance to audiologists, related professionals, and consumers of occupational and nonoccupational hearing conservation services in the following areas:
preparation of the audiologist to provide hearing conservation services;
role of the audiologist on the interdisciplinary team in hearing conservation;
components of service delivery in hearing conservation; and
professional ethics related to service delivery in hearing conservation.
The profession of audiology developed as a response to hearing problems stemming from noise exposure, specifically military noise exposure during World War II (McLauchlin, 1978). After this initial development phase, the profession gradually turned its research and academic interests toward other areas of audiological practice. Many audiologists affiliated with military and VA facilities were involved in occupational hearing conservation efforts. After compensation claims for noise-induced hearing loss began to be filed in the late 1940s and early 1950s, interest in occupational hearing conservation grew in the private sector.
In 1965, the U.S. Department of Labor included “industrial audiology” in a list of specializations recognized as part of audiological practice in its Dictionary of Occupational Titles.
In 1969, the U.S. Department of Labor issued a noise standard under the authority of the Walsh-Healy Public Contracts Act. This standard was subsequently extended to the majority of American workers under the Occupational Safety and Health Act of 1970 and the 1971 Occupational Noise Exposure Standard. In 1974, the Department of Labor proposed a revision to the noise standard, which included requirements for hearing conservation programs.
On January 16, 1981 (U.S. DOL, 1981a), OSHA issued a standard for hearing conservation programs as an amendment to the existing noise standard. Because the standard was published so close to the advent of a new Presidential administration, the effective date of the standard was delayed. Portions of the standard became effective on March 8, 1983 (U.S. DOL, 1983). ASHA was instrumental in achieving enactment of the amendment through its testimony and that of many of its members. This final rule specifically names the audiologist as one of three categories of professionals responsible for the audiometric testing program. (For additional information on the development of federal noise standards, refer to Suter's chapter in Lipscomb ).
Federal regulations related to occupational noise exposure have enhanced further interest and activities among audiologists and other professionals in the area of occupational hearing conservation. Concomitantly, public awareness of the effects of noise has grown in recent years, creating opportunities for professional participation.
Historically, ASHA has been involved with issues related to noise and its effects on humans (McLauchlin, 1978). ASHA's publications on this topic include ASHA Monograph Supplements numbers 1 (Kryter, 1950), 3 (Loring, 1954), and 28 (Suter, 1991), and ASHA Reports numbers 4 (Ward & Fricke, 1969) and 10 (Tobias, Jansen, & Ward, 1980). The Association sponsored a National Conference on Noise as a Public Health Hazard in 1969 and has actively supported all six of the International Congresses on Noise as a Public Health Problem. In 1964 and 1965, ASHA participated in the development of a “Guide for Training of Industrial Audiometric Technicians” (American Industrial Hygiene Association, 1966) as a member of the Inter-Society Committee on Audiometric Technician Training. This committee evolved in 1973 into the Council for Accreditation in Occupational Hearing Conservation (CAOHC), of which ASHA continues to be a component professional organization with two delegates to the Council. The Guide was later replaced by the “CAOHC Outline for Course Leading to Accreditation as an Occupational Hearing Conservationist” (CAOHC, 1991).
ASHA has been a leader and participant in many collaborative efforts in the legislative and political arena. In 1991, ASHA led a coalition to lobby OSHA for a stronger criterion for hearing loss recordability on the OSHA Form 200. This coalition consisted of representatives from ASHA, the National Hearing Conservation Association (NHCA), the American College of Occupational and Environmental Medicine (ACOEM), the American Academy of Otolaryngology-Head & Neck Surgery (AAO-HNS), and CAOHC. Also in 1991, ASHA convened a meeting at the request of Rep. Richard Durbin (D-IL) that was cosponsored by the Acoustical Society of America (ASA) and the AAO-HNS. Durbin distributed the proceedings of the meeting, “Combating Noise in the 90's: A National Strategy for the United States,” to members of Congress. In 1994, representatives of NHCA and ASHA met with OSHA Secretary Joseph Dear to discuss proposed reform of the OSHA noise standard.
The foregoing historical account documents that for many years audiologists have been actively involved in the prevention and assessment of NIHL and in assisting industry in the development of occupational hearing conservation programs.
Because hearing conservation is an evolving field, concerned audiologists must be aware of emerging and ongoing issues. The following issues are not listed in any particular order and are not all encompassing. Other issues will certainly arise in the future.
Nonoccupational exposures to hazardous noise continue to harm the hearing health of individuals of all ages. Currently, no standards exist for these exposures.
Public awareness of the hazardous effects of excessive noise should be initiated at an early age to instill appropriate behaviors. There are several educational programs available for all ages (see Appendix).
Many workers exposed to hazardous noise (e.g., workers in construction, agriculture, and oil well drilling and servicing) are either not covered or inadequately covered by hearing conservation regulations.
There is general professional agreement that the OSHA and MSHA regulations represent minimal requirements for an effective hearing conservation program. “A Practical Guide to Effective Hearing Conservation Programs in the Workplace” (NIOSH, 1995) sets forth the concepts and techniques that a body of experts have found to be consistent with successful hearing conservation programs.
Recent research suggests that some chemicals not only are ototoxic in and of themselves but also act synergistically with noise to produce an injurious effect on the auditory system.
Community noise is a growing concern for urban planners and local governments.
Monitoring audiometry, whether part of a hearing conservation program or school health program, may identify potentially treatable conductive and retrocochlear pathologies as well as NIHL. Cost-effective referral criteria should be developed.
The Americans with Disabilities Act (ADA) affects the hiring and/or retention of employees with hearing loss in noise-hazardous or hearing-critical jobs. A problem faced by audiologists and other health and safety professionals is the lack of objective measures with which to predict the ability of an individual with hearing loss to perform job-related tasks.
Labeling of the attenuation values on hearing protection devices (HPDs) does not reflect actual field performance. Efforts should continue to develop more accurate and useful estimates of HPD effectiveness.
Active noise reduction shows promise for reducing the hazardous levels of noise in certain environments. Its usefulness is limited to relatively stable, low-frequency noises. Other specialized HPDs, such as flat attenuation and moderate attenuation devices, may be appropriate in certain environments and for certain individuals.
Testing of otoacoustic emissions may provide predictive information to identify noise-sensitive individuals.
The ability of individuals with hearing loss, as well as those individuals with normal hearing, must be considered in the design and use of warning signals. This area of psychoacoustics involves many disciplines; more involvement by audiologists is needed.
Preservice Education. Generally, graduate education programs in audiology that are accredited by ASHA's Council on Academic Accreditation (CAA [Note: In January 1996, the Educational Standards Board became known as the Council on Academic Accreditation]) offer basic preparation in the area of noise and hearing conservation. In recent years, many graduate programs have expanded their offerings in noise and hearing conservation because of increased interest on the part of audiologists and the general public in this area. Some programs offer special curricula in the area of occupational audiology. These curricula supplement a basic program of study in audiology with specialized courses and reference materials from other university departments, such as industrial hygiene, engineering, business, and public health.
An ideal graduate audiology program emphasizing hearing conservation will have, as its core, standard audiology course work as defined by the CAA. This will be supplemented by other specialized courses and practicum experiences relevant to the skills and knowledge needed by the professional intending to work in the area of occupational hearing conservation.
Audiologists intending to work in hearing conservation should have specialized course work in the following areas:
auditory disorders, such as (a) pathologies of the auditory system, and (b) assessment of auditory disorders and their effect on communication;
habilitative/rehabilitative procedures, such as (a) selection and use of appropriate amplification instrumentation for the hearing impaired, and (b) management procedures for speech and language habilitation and/or rehabilitation of the hearing impaired (that may include manual communication);
conservation of hearing, such as (a) environmental noise control, and (b) identification audiometry (school, military, industry); and
instrumentation, such as (a) electronics, (b) calibration techniques, and (c) characteristics of amplifying systems (ASHA, 1994).
In addition to the core curriculum of standard audiology course work, the audiologist intending to work in hearing conservation should have training in:
auditory and nonauditory effects of noise on humans, including damage risk criteria and effects on communication and job performance;
federal, state, and local noise regulations;
worker compensation regulations and trends;
performance, fitting, and physical characteristics of personal hearing protectors;
methods of evaluating the effectiveness of hearing protectors;
criteria of CAOHC and other requirements for training occupational hearing conservation technicians;
personnel education and motivational techniques;
use of predictors such as the Articulation Index for the effect of noise in masking of speech;
noise measurement instrumentation and techniques for conducting noise surveys;
principles of noise control;
business and human resources management;
information management techniques and applications;
marketing of audiology services; and
business report writing.
The audiologist-in-training should have extensive practicum experience in working on-site in an industrial setting under the supervision of an audiologist experienced in occupational hearing conservation. This practicum should include activities in all seven of the components of a model hearing conservation program (see Components of Service Delivery in Occupational Hearing Conservation below).
In-Service Education. Many educational opportunities exist for audiologists already working professionally to expand skills and knowledge in hearing conservation. These include continuing education programs offered by professional associations (e.g., ASHA, NHCA, ASA, AIHA, American Academy of Audiology), universities, and equipment manufacturers.
Audiologists should be qualified by education and experience to assume a leadership role in the development and implementation of occupational hearing conservation programs. In this role, they should involve members of other disciplines and coordinate activities to enhance the proper development and operation of effective hearing conservation programs. The other professional disciplines may include acoustical engineering, industrial engineering, otolaryngology, occupational medicine, safety engineering, occupational nursing, industrial hygiene, human resource management, and information management. The extent of involvement of each discipline will be determined by the employers' needs and resources.
A model hearing conservation program includes seven general components:
noise exposure assessment;
engineering and administrative controls of noise exposure;
personal hearing protection;
audiometric testing, audiogram review, and referral;
worker and management education and motivation;
analysis of program effectiveness.
In addition to the basic components of an effective OHCP, audiologists may be involved in forensic activities, such as serving as expert witness in hearing loss compensation claim cases and other forms of litigation.
The audiologist participates in each program component to a greater or lesser extent depending on his or her education and skills and the particular employer's needs and resources. The audiologist can advise management on all operational aspects of the hearing conservation program, including management responsibilities and liabilities under federal, state, and local occupational health and safety regulations and worker compensation statutes. The audiologist can recommend the most efficient means of completing each component of the program.
Employers should be aware that the scope of practice of occupational hearing conservation technicians is limited (CAOHC, 1993).
The purpose of noise exposure monitoring is to determine the need for implementation of, and appropriate strategies for, an effective hearing conservation program. The audiologist, industrial hygienist, or acoustical engineer, with the appropriate background and training, performs area noise measurement, personal dosimetry, and related equipment calibration activities. Alternatively, these professionals may choose to train and supervise a person within the organization or recommend a consultant to perform these activities.
The preferred method to reduce employee noise exposure is implementation of engineering and/or administrative controls. Engineering controls of noise are usually the domain of the acoustical engineer or other consultants with noise control expertise. The feasibility of administrative noise controls should be determined by the employer. The audiologist should be involved in consultation to determine the effectiveness of these types of controls. The audiologist should be familiar with engineering consultants whom he or she can recommend to the employer.
When engineering and/or administrative controls are not feasible, a personal hearing protection program must be implemented. The audiologist is the key team member in solving problems related to the use of HPDs. Such problems may include the inability to hear speech and other signals and the inability to reduce exposures to a “safe” level. The audiologist should advise the employer on the selection of appropriate personal hearing protection, given the nature and extent of employee noise exposures and knowledge of attenuation characteristics of specific types of hearing protectors. The audiologist can fit personal hearing protection and instruct and motivate the worker regarding its proper use and care. The audiologist can also train and supervise technicians in appropriate procedures for dispensing hearing protectors to workers.
Audiometric testing, review, and referral are central to the mission of an occupational hearing conservation program. The effectiveness of the program and the hearing threshold integrity of individuals are assessed through ongoing monitoring of the hearing levels of noise-exposed personnel. The audiologist should take a leadership role in the delivery of the following services:
advise management on the relative merits of different approaches to audiometric testing (inhouse, mobile, or off-site; by in-house staff, contractors, or clinical providers);
advise management on the suitability of various types of audiometers (e.g., manual, self-recording, microprocessor, software-driven);
train, retrain, and supervise occupational hearing conservation technicians;
select and ensure calibration of audiometric equipment;
select suitable audiometric testing areas and document ambient noise levels;
provide or recommend appropriate audiometric services;
review and interpret audiometric tests performed by occupational hearing conservation technicians;
develop and implement re-test and referral criteria for use by technicians and management;
refer to appropriate medical services for otologic examination.
One of the most important components of an effective hearing conservation program is worker and management motivation and training. The audiologist may perform the following activities:
develop or recommend appropriate materials;
instruct in-house staff in effective methods of motivating and educating workers;
contribute to management education by preparing articles for publications or speaking before trade and management groups; and
maintain up-to-date knowledge of pertinent local, state, and federal regulations in order to provide management with accurate information concerning these matters.
An accurate and complete record-keeping system is a requisite element of an OHCP to verify compliance with relevant standards and to ensure program effectiveness. The audiologist should advise the employer of required and recommended records that should be maintained in-house to document each of the components of the program. In addition, the audiologist should establish and maintain an adequate recordkeeping system for all services — whether direct, supportive, or consultative — provided for an employer.
Analyzing the effectiveness of a hearing conservation program provides meaningful feedback to all levels of personnel within an organization. Analysis of HCP effectiveness:
assesses the regulatory compliance and effectiveness of the HCP through on-site audits of program activities and statistical analyses of audiometric databases;
provides evaluation of hearing threshold changes and patterns in various worker populations and individuals and assists management in determining an appropriate course of action;
detects specific problem areas where improvement may be needed in the program;
provides important information to management on the benefits derived from the program; and
identifies quality improvement issues (e.g., trends in elevated thresholds at 500 Hz that may indicate excessive ambient noise levels, a pattern of elevated thresholds for a given audiometer indicating a possible equipment malfunction or examiner error, etc.).
The above list is in no way comprehensive. Rather, it is included to provide the reader with some rationale for including program analysis as a component of a complete hearing conservation program.
Preservation of the highest standards of integrity and ethical principles is vital to the responsible discharge of obligations in the profession of audiology. The ASHA Code of Ethics (1994) sets forth the fundamental principles and rules considered essential to this purpose. It contains several principles and rules that are especially relevant to the provision of hearing conservation services.
Principle of Ethics I states that “individuals shall honor their responsibility to hold paramount the welfare of persons they serve professionally.” The audiologist providing services under contract or on a fee-for-service basis must attempt to the best of his or her ability to serve the welfare of both the employer and the exposed individual. This principle relates specifically to the area of audiometric testing, audiogram review, and medical/audiological referral. Information regarding auditory status and related matters should be made available to the exposed individual.
Principle of Ethics I, Rule E, states that “individuals shall evaluate the effectiveness of services rendered and products dispensed and shall provide services or dispense products only when benefit can reasonably be expected.” The audiologist providing or supervising hearing conservation services must develop or use currently available methods of measuring the effectiveness of these services and products.
Principle of Ethics II states that “individuals shall honor their responsibility to achieve and maintain the highest level of professional competence.” An audiologist intending to provide hearing conservation services must be properly prepared to offer these services through either preservice and/or in-service training and experiential activities.
Principle of Ethics II, Rule D, states that “individuals shall delegate the provision of clinical services only to persons who are certified or to persons in the education or certification process who are appropriately supervised. The provision of support services may be delegated to persons who are neither certified nor in the certification process only when a certificate holder provides appropriate supervision.” It is the responsibility of audiologists who supervise hearing conservation technicians in hearing testing, personal hearing protection fitting, and record keeping to maintain adequate supervision of such persons to ensure their continued competency.
Occupational and nonoccupational noise exposure poses a continuing hazard to the hearing health of millions of individuals. The development and implementation of effective hearing conservation programs can and will prevent needless cases of hearing loss. Audiologists are especially qualified to exercise a leadership role in the development and implementation of hearing conservation programs. This position statement has addressed issues germane to the participation of audiologists in hearing conservation programs, including the nature and extent of such participation, academic and experiential requirements, and standards of professional conduct. Its purpose is to provide guidance to audiologists, other professionals, and the industrial community.
American Industrial Hygiene Association. (1966). Training requirements specified by the Inter-Society Committee on Audiometric Technician Training. American Industrial Hygiene Association Journal, 27, 303–304.
Tobias, J. V., Jansen, G., & Ward, W. D. (1980). Proceedings of the Third International Congress on Noise as a Public Health Problem (ASHA Reports No. 10). Rockville, MD: American Speech-Language-Hearing Association.
American Industrial Hygiene Association. (1966). Training requirements specified by the Inter-Society Committee on Audiometric Technician Training. American Industrial Hygiene Association Journal, 27, 303–304.
American Speech-Language-Hearing Association. (1994). Occupational hearing conservation: the current picture (cassette recording from teleseminar held October 28, 1994). Rockville, MD: American Speech-Language-Hearing Association.
Berger, E. H., Ward, W. D., Morrill, J. C., & Royster, L. H. (Eds.). (1988). Noise and hearing conservation manual (4th ed.). Fairfax, VA: American Industrial Hygiene Association. Order from: AIHA, 2700 Prosperity Avenue, Suite 250, Fairfax, VA 22031. (703)849-888.
Hearing Education and Awareness for Rockers (H.E.A.R.) is a nonprofit organization dedicated to the education of musicians and others about noise-induced hearing loss. For information: H.E.A.R., Kathy Peck, Executive Director, University of California-San Francisco Center on Deafness, 3333 California Street, Suite 10, San Francisco, CA 94118.
HIP Talk (Hearing Is Priceless) contains a videotape and educational curriculum for junior and high school students to stimulate student awareness of the dangers of exposure to loud volumes of sound over extended lengths of time. For information: House Ear Institute, 2100 West Third Street, Fifth Floor, Los Angeles, CA 90057.
I love what I hear! contains a videotape and educational curriculum for grades 3–8 to designed to introduce children to the study of hearing science and to build awareness of the importance of hearing conservation. For information: National Institute on Deafness and Other Communication Disorders, NIDCD Clearinghouse, P.O. Box 37777, Washington, DC 20013-7777.
Know Noise contains a videotape, two cassette tapes, and educational curriculum in a contemporary format of rap music and interactive exercises to educate schools and youth groups about hearing health. For information: The Sight and Hearing Association, Carol Roney, 674 Transfer Road, St. Paul, MN 55114.
Operation BANG (Be Aware of Noise Generation) is a public awareness program developed to educate younger generations to be aware of noise and to educate the public about hearing conservation and the profession of audiology. Developed by the Air Force Audiology Association Public Relations Committee.
Operation SHHH contains an automated sound-operated stoplight as well as activity charts to teach children about noise. For information: Self Help for Hard of Hearing People, Inc., 7910 Woodmont Avenue, Suite 1200, Bethesda, MD 20814.
Stop That Noise! contains educational curriculum for grades 4–7 designed to teach young people how to protect and conserve their hearing. For information: League for the Hard of Hearing, 71 West 23rd Street, New York, NY 10010.
[*] Note: Any previous references to “hearing conservation” in this document have applied to both occupational and nonoccupational settings. Nonoccupational hearing conservation is essentially the application of occupational hearing conservation activities in nonoccupational settings. The remainder of this document will focus on occupational hearing conservation practices.
Index terms: hearing conservation
Reference this material as: American Speech-Language-Hearing Association. (1996). The audiologist's role in occupational and environmental hearing conservation [Position Statement]. Available from www.asha.org/policy.
© Copyright 1996 American Speech-Language-Hearing Association. All rights reserved.
Disclaimer: The American Speech-Language-Hearing Association disclaims any liability to any party for the accuracy, completeness, or availability of these documents, or for any damages arising out of the use of the documents and any information they contain.