Workplace Integra Hearing Conservation &
Health Data Management

Contact Workplace INTEGRA at (888) WPI-0001 or by for more information.

An Overview of the Occupational Hearing Conservation Programs:

The Audiologist’s Role, Audiologic/Medical Referrals, and Expectations Concerning Referrals

By George Cook, Au.D., CCC-A

The following article, An Overview of the Occupational Hearing Conservation Program: The Audiologist’s Role, Audiologic/Medical Referrals, and Expectations Concerning Referrals, was written by Workplace Group’s Senior Occupational Audiologist, George R. Cook, CCCA, for the American Speech, Language and Hearing Association, Special Interest Group Newsletter. The April, 2004, ASHA Newsletter featured Noise and was sent to over 800 clinical and occupational audiologist world wide. The intent of the article was to educate and inform clinical audiologist and otologist about the needs of company’s referring employees for medical evaluation and diagnosis from their occupational hearing conservation programs.

The article is being sent to Workplace Group Newsletter subscribers as a tool to better inform their local otologic and/or audiologic clinics of the company’s needs when making medical referrals from their hearing conservation program.

Employees from occupational hearing conservation programs often do not get the expected and needed type of evaluation, diagnosis or treatment from the clinical audiologist or physician. Often there is a misunderstanding about how an occupational hearing conservation program works, what an occupational audiologist does as well as what the management, employee and occupational audiologist expect from the clinical audiologist and physician.

The following cases demonstrate the problem.

In the first case, a medical referral was made for a middle-aged female employee who showed a change in hearing with a mild, flat, hearing loss, bilaterally. She was exposed to significant levels of noise with a 92-dBA time weighted average (TWA).

The employee and supervisor reported that the employee wore hearing protection devices (HPDs) consistently. The employee demonstrated correct insertion of the HPDs. A tuning fork test suggested a possible conductive component. The employee was referred to an otologic clinic for diagnosis at the company’s expense. Company medical notes and audiograms were sent to the clinic.

The report from the clinic showed noise-induced hearing loss as a diagnosis in view of positive otoacoustic emissions (OAEs) and indications of Eustachian tube dysfunction. When challenged, the audiologist offered to change the diagnosis.

In the second case, a 36-year-old male fabrication shop employee was presented with a significant change in hearing and difficulty hearing in the presence of noise. The employee worked in a machine shop using drill presses and machine lathes with a TWA below 85 dBA for the past 15 years. Hearing protection was available and reportedly worn when job activities involved loud noise, such as hammering, grinding, and chipping. These activities were limited.

The audiogram showed a flat 30 dB HTL (+ 5 dB) bilateral sensorineural hearing loss. OAEs were absent and discrimination was good. No testing of speech or words in noise was done. The diagnosis was noise-induced hearing loss. When challenged, the audiologist indicated OAEs were absent and the employee worked at a manufacturing plant.

In truth, the configuration of loss is not common to noise. It is understandable that noise cannot be ruled out for contributing to the loss. But, what other pathologies or conditions could cause or aggravate the employee’s hearing loss? Every known pathology causing hearing loss will probably pass through an occupational hearing conservation program. If the program is a good one, any of those pathologies will get a clinical referral, except beginning noise-induced hearing loss.

The role of noise in creating hearing loss

Noise-induced hearing loss and acoustic trauma will create a notch at either 3, 4, or 6k Hz or at 3 and 4k Hz, or even at 4 and 6k Hz. The lower frequencies maintain their integrity. The loss will progress to a precipitous high frequency loss looking much like aging in the later stages (Burns, 1968). However, even though noise is the most prevalent occupational health exposure (Berger, Royster, Royster, Driscoll, and Layne, 2000), it is not the only occupational exposure found in the workplace that may cause or contribute to hearing loss (Cary, Clarke and Delic, 1997).

We have known for many decades that heavy metals will produce site-specific sensory and neural hearing loss (Rybak, 1992). Since the early 1990’s aromatic solvents have been identified as having a synergistic effect with noise to produce hearing loss (Morata, Dunn, Kretshchmer, Lemasters, and Keith, 1993). Safe levels of noise and safe levels of toluene exposure can result in hearing loss. Nor is susceptibility to noise due to occupational or environmental agents alone. Cholesterol levels, hypertension, diabetes, and metabolic conditions can produce hearing loss or predispose individuals to noise. The list of medications causing or contributing to hearing loss in the presence of noise is astounding with the most notable being antibiotics, arthritics, steroids, chemotherapy, and hypertension medications (DiSogra, 2001).

How a hearing conservation program works

Most audiologists are aware of the requirements of the Occupational Safety and Health Administration (OSHA) Noise Standard 1910.95 (OSHA, 1983). Companies are required to monitor noise levels in the plant. If levels create an exposure over 90 dBA TWA (Permissible Exposure Level or PEL), they are required to implement noise control, dispense and enforce the wearing of hearing protection, and institute a continuing effective hearing conservation program including baseline and annual hearing testing (pure tone), as well as an annual hearing conservation education. If levels exceed 85 dBA TWA (Action Level), companies are required to conduct hearing testing, annual education and have hearing protection available. If a change in hearing occurs, the employers are required to fit or refit hearing protection, enforce the wearing of hearing protection on employees exposed to levels at or exceeding the Action Level and inform the employee in writing of the change in hearing within 21 days. A change in hearing is defined as the occurrence of a Standard Threshold Shift (STS) or an average of 10-dB change at 2, 3, and 4k Hz in either ear.

Role of the Occupational Audiologist

Three regulations give the audiologist a significant role in occupational hearing conservation and the medical referral process. Both OSHA and Mining Safety and Health Administration (MSHA) require professional supervision of the hearing testing, test review and testing technicians (OSHA, 1999; OSHA 2002). This professional reviewer may be a certified audiologist or a physician. The third regulation is the Occupational Injury and Illness Recording and Reporting Requirements (OSHA, 2001; OSHA, 2002). As part of the history of logging, the original intent of the OSHA Occupational Injury and Illness Recording and Reporting Log was to gather statistics on the national occurrence of job related illnesses and injuries. The agency has ceased to be the Office of Statistics and has been moved under OSHA where it is now used in part to police industry. High incidence rates trigger OSHA investigations. To avoid OSHA investigations, management creates incentives to keep entries off the OSHA 300 Log.

Since July 1, 2002, the finalized rule allows a physician or other licensed health care professional to determine work relatedness of hearing loss. Other licensed health care professionals are "an individual whose legally permitted scope of practice (i.e., license, registration, or certification) allows him or her to independently perform, or be delegated the responsibility to perform, the activities described by this regulation" (OSHA, 2001). Audiologists qualify for determining job relatedness for purposes of recording hearing loss on the OSHA 300 Log. Item 9 of the Audiologist’s Role in the document titled the Occupational Hearing Conservation and Hearing Loss Prevention Programs states that the audiologists’ role is to "determine or assist in determining, through evaluation or referral, work-relatedness of hearing loss for the purposes of otologic and/or audiologic referral and recording on the OSHA 300 Log" (ASHA, 2004).

Referral process

In an occupational hearing conservation program, hearing tests are performed, those tests are reviewed and a disposition is given to the "problem" audiograms. This disposition may involve follow-up at the plant as verification of the fit and wearing of hearing protection or the disposition may indicate medical follow-up. How hearing tests are selected for review can have an affect on the medical referral process. One way in which audiograms are selected for review is by the technician doing the test. The OSHA standard allows technicians to identify "problem" audiograms to be passed on to the audiologist. There are commercial hearing test providers that have their non-professional technician staff identify which audiograms go to the audiologist or physician for review. This is not the best method because the quality of the total review process is left to the non-professional selecting the "problem" audiogram. Fortunately, there seems to be only a few of these providers.

There are times when an audiologist manually reviews all hearing tests from a plant or mobile unit. However, computer software does many of the reviews. In service companies providing hearing test reviews for mobile vans or plants that do their own testing, the computer software, using certain criteria, identifies the employee with the problem audiogram. These programs have various degrees of sophistication from only identifying employees with STS’s to integrating and screening a variety of other criteria, such as additional threshold changes, loss configurations, amount of loss expected for age, otoscopic observation and answers to history questions. Some software programs use the Otologic Referral Criteria for Occupational Hearing Conservation Programs (AAO, 1997).

Regardless of the sophistication of the software, either the computer determines medical referrals or an audiologist reviewing the problem audiograms selected by the computer determines the medical referrals. When the computer determines medical referrals, an audiologist may not be on the full-time staff. Service companies may report that the audiologist on the Board or on contract has provided an overview of the software and given it their approval. They may even sign off on batches of hearing tests being processed, but I have observed that they review very few hearing tests because of the many batches of data and amount of time required. In these service companies, the audiogram is usually flagged with a code, for example A4 or D12. The company receiving the reviews then looks up the code or the reports are labeled as "Medical Referral".

In service companies where software has selected the employee’s records for an audiologist to review, the audiologist is presented with the reason for review, the employee’s previous hearing tests on record, any comments made by the technician, the audiological history questionnaire as well as the past review information. After observing the configuration of loss, amount of change, history and comments, the audiologist gives the case disposition for plant or medical follow-up.

The reviewing audiologist makes two distinctly different types of referrals. The first type is a medical referral, identified in 1910.95 (OSHA, 1983). The reviewing audiologist has determined by the configuration of the audiogram, amount of change, configuration of change, technician comments, employee comments, otologic history, and otoscopy that the hearing loss is non-occupational, that the employee needs to be informed that they have a hearing problem and that they need to see a physician for diagnosis and possible treatment.

The employee’s loss would commonly be of a flat configuration, perhaps in one ear, with a suspected conductive component and suspected history or employee presentation. When referring based on configuration, a baseline audiogram can warrant a medical referral, especially when there is no evidence the employee has ever seen a physician for his or her ears or for hearing loss. In cases of medical referral the company is required to inform the employee that they have a hearing problem and that they need to see a physician. Because of the liability of knowing an employee has a medical problem and not informing the employee of the need to see a physician, companies will maintain documentation and the employee signs a medical referral slip that is kept on file. Many times the employee will be given a copy of his hearing tests and be asked to sign the referral. In these cases, the employee makes the appointment and the employee or employee’s insurance company pays for the medical evaluation.

The second type of referral is where an STS has occurred and the hearing change is or is suspected as occupational. In this type of referral, the company is looking for the possible cause of the hearing change, as well as treatment measures and possible remediation steps that may be taken to prevent additional hearing loss. The company also needs a diagnosis of occupational or non-occupational relatedness in a report with proper releases. This is necessary for them to qualify the hearing loss as an OSHA recordable. When the audiologist indicates this type of referral, the company makes the appointment, sees that the employee gets to the appointment and pays for the medical referral.

Expectations concerning the referrals

A medical referral for non-occupational hearing loss comes with the same expectations as any office visit by a patient presented with a problem. The clinical audiologist could expect to have information concerning the reason for referral and a copy of all the employee’s past hearing tests by the company, including otologic/audiologic history and an indication of noise exposure. If the company has a good hearing conservation program and an audiologist is reviewing audiograms, beginning noise-induced changes in hearing would not warrant a medical referral for determination of occupation or non-occupational causation. If the audiogram has a configuration of change common to beginning noise, the audiologist would instruct the company to check the employee’s fit and proper use of hearing protection and require the employee to wear hearing protection when in noise on the job as well as and encouraging the employee to wear protection when in noise off the job. Not all STS’s have a medical referral indicated for follow-up. The employee with hearing that suddenly drops, has a unilateral change, or has hearing changes that are greater than expected given his or her noise exposure or age, or has other medical conditions or medications that make it difficult to determine if noise is involved receives a referral.

In many plants, the audiologist visits the plant to screen medical referrals and qualify employees for OSHA 300 Logging. At that time, tuning fork testing, tympanometry, or OAE testing may be conducted to screen referrals. The company needs and expects an evaluation as to the cause of the hearing loss when an outside referral is made. It does not need or expect a diagnosis based on the assumption that because it is an industry referral, the employee has noise-induced hearing loss. The reason adequate evaluation is needed is first for the employee so additional loss can be avoided and any treatment may be made available. Secondly, if the loss is non-occupational, it is not recorded on the OSHA 300 Log. To dispel any suspicions of a hidden-agenda by the author, there are managers who would like all STSs to be diagnosed as non-occupational and therefore non-recordable. However, many managers would appreciate an in depth evaluation with a diagnosis.

Wording is also important. Unless it is known for certain that the loss is recordable, it is best not to indicate, "OSHA recordable," but "possible OSHA recordable" because it creates a ‘smoking gun’ in the paperwork within the company. An audiologist may visit the plant at a later date and after interviewing the employee, reviewing the medical records, visiting the work area, and discovering the employee has no significant noise or substance exposures that the change in hearing is not occupational, the audiologist or physician would have to change the disposition in view of previous instructions, "OSHA recordable". The indication of "possible OSHA recordable" permits the company to work through the justification and documentation in the event the loss is determined non-work related in the future by an audiologist or another qualifying professional (OSHA, 2001). If an audiogram were identified as a "possible OSHA recordable", the company would have to provide sufficient documentation as to why it was not recorded. The ultimate responsibility for recording belongs to the company. There have been situations where the clinical audiologist labeled "OSHA recordable" and later, after thorough review at the plant, found that it was clearly not work related.


Occupational hearing conservation programs need help with medical referrals. Why did this individuals hearing change so drastically, especially in view of the employee’s age, or the unusual configuration of change, or limited noise exposure? Are there other medical conditions that are contributing to the change? Are there sub-clinical metabolic conditions? Are there things that could be done to prevent additional loss, as a change in medications or diagnosis and treatment of a medical condition? If the hearing change was common to beginning noise exposure, the employee would likely not get a medical referral, they would have a follow-up at the plant with hearing protection fitting and enforcement. The dramatic and difficult cases get the referral to the clinical otologist and audiologist.


American Academy of Otolaryngology. (1997). Otologic Referral Criteria for Occupational Hearing Conservation Programs, Medical Aspects of Noise Subcommittee of American Academy of Otolaryngology.-Head and Neck Surgery, Washington, DC.

American Speech-Language Hearing Association. (2004). The Audiologist’s Role in Occupational Hearing Conservation and Hearing Loss Prevention Programs: Technical Report. ASHA Supplement 24, in press.

Berger, E. H., Royster, L. H., Royster, J. D., Driscoll, D. P., and Layne, M. (2000). The Noise Manual, (5th ed.). American Industrial Hygiene Association Press: Fairfax, VA.

Burns, W. (1968). Noise and Man. JB Lippincott: Philadelphia, PA.

Cary, R., Clarke, S., and Delic, J. (1997). Effects of combined exposure to noise and toxic substances: Critical review of the literature. Annals of Occupational Hygiene 41, 455-465.

DiSogra, R.M. (2001) Adverse drugs reactions and audiology practice. Audiology Today. September, Special Issue, 2-19.

Health Standards for Occupational Noise Exposure; Final Rule, 30 CFR Part 62, 64, Occupational Safety and Health Administration, Federal Register.§ 49458-49634, §49636-49637 (1999).

Occupational Injury and Illness Recordkeeping and Reporting Requirements, Safety and Health Administration, Federal Register. 66 (13) (2001).

Occupational Injury and Illness Recordkeeping and Reporting Requirements; Final Rule, Occupational Safety and Health Administration, Federal Register. 67, §44037-44048 (2002).

Occupational Noise Exposure: Hearing Conservation Amendment; Final Rule, Occupational Safety and Health Administration, 29CFR1910.95 Federal Register 46 (162), §42622-42639 (1983).

Morata, T.C., Dunn, D. E., Kretshchmer, L.W., Lemasters, G. K., and Keith, R. W. (1993). Effects of occupational exposure to organic solvents and noise on hearing. Scandinavian Journal of Work Environmental Health 19 (4), 245-254.

Rybak LP (1992). Hearing; The effects of chemicals. Otolaryngology Head Neck Surgery 106, 677.

Return to top

Better Business Bureau Logo

| | Privacy policy

© Copyright 2018, Workplace INTEGRA, Inc., Greensboro, North Carolina

Workplace INTEGRA, Inc.
420-B Gallimore Dairy Road
Greensboro, NC 27409
FAX: 336-856-2945