Prolonged exposure to hazardous noise can have harmful effects on workers' health. Monitor the hearing health status of the noise-exposed workers to identify changes and take action to prevent further damage.
An audiometric testing program checks the hearing thresholds of workers and tracks them over time. The objective is to detect changes or shifts in hearing that may signal the beginning stages of noise-induced hearing loss (NIHL). Identifying the signs and symptoms early allows employers to intervene before the symptoms get worse Therefore, part of the audiometric testing program is to ensure that effective follow-up actions are taken.
Audiometric monitoring programs depend on checking hearing thresholds in a consistent, standardised manner, using trained and competent personnel. The test room should be quiet enough to minimise distractions for valid thresholds to be obtained. A baseline hearing check (audiogram) done before the worker’s first exposure to hazardous noise is then compared to future, routine hearing checks. Typically done annually, these results help to identify problems, such as hearing threshold shifts.
Audiometric test programs can be offered in a variety of ways, including in-house testing, mobile service providers, or at a health clinic. They may be performed by an audiologist or physician, but are most commonly done by audiometric technicians or occupational hearing conservationists with speciality training. Any “problem audiograms” must be reviewed by an audiologist or physician to help determine follow-up actions. For example, in some cases, medical follow-up is necessary. If permanent hearing loss occurs, a professional can help determine whether it is related to noise on-the-job.
The audiometric results can be used on an individual basis to teach workers about their hearing health status. Also, the whole audiometric database can be analysed to identify trends and develop appropriate intervention plans. The results of the hearing checks should trigger follow-up actions.
Scheduling the tests is somewhat dependent on the method chosen for delivering them. For example, the testing can be spread throughout the year or done within the same week or month every year. Some considerations for scheduling are the time or season of the year, the start and end times of the work shift, and the availability of workers to be away from job tasks. Employees who need a baseline test should avoid workplace noise exposure for 14 hours, or wear hearing protection, before the test.
Conducting hearing checks also gives other opportunities to interact with workers. Extra training can be provided and the condition and fit of the hearing protection can be checked.
Requirements for audiometric testing are detailed in the OSHA 29 CFR 1910.95 Hearing Conservation Amendment. The following is a brief summary of the requirements; the regulation itself should be consulted for actual language and/or use. Note that state OSHA plans may also have additional requirements.
Who must have an audiometric test?
All employees who are exposed at or above the OSHA action level (85 dBA TWA) must be in an audiometric monitoring program.
Who can perform the audiometric test?
Testing can be completed by a licensed or certified audiologist, otolaryngologist (ear, nose, and throat physician), or other physician, OR by a certified technician. Certification for audiometric technicians is available through the Council for Accreditation in Occupational Hearing Conservation (CAOHC). See www.caohc.org. If the technician is not certified, he or she must be able to demonstrate competency. All technicians who conduct hearing tests must be responsible to an audiologist or a physician.
Done within the first 6 months of noise exposure at or above 85 dBA TWA unless a mobile test van is used. In that case up to 12 months is allowed, however, hearing protection must be used if the test is done after 6 months.
There must be a 14-hour period of no workplace noise exposure before the baseline test. Hearing protection is allowed to be used as a substitute for the 14-hour noise-free period.
Annual tests must be completed every 12 months or sooner and may be conducted at any time during the work shift.
Retest: if a worker shows STS on the annual test when compared to the baseline, a retest may be done within 30 days of the annual test. The retest is optional.
The background noise where the hearing test is conducted must meet specific noise levels:
OSHA MAXIMUM ALLOWABLE OCTAVE-BAND SOUND PRESSURE LEVELS* FOR AUDIOMETRIC TEST ROOMS
*Permissable noise for ears covered with MX-41/AR cushions.
Answers to common questions per OSHA 1910.95
Employee noise exposures at 85 dBA TWA and above
Within 6 months of first noise exposure or within 12 months, if mobile van service is used. Hearing protection is required if baseline audiogram is not obtained within 6 months.
Yes, but only if hearing protection is worn during the noise exposure.
Yes, assuming that the clinic can meet the OSHA test requirements and that there is no cost to the worker by doing so.
Yes, however the hearing test must be done without the hearing aid. If necessary, the worker could be tested by an audiologist.
Yes, however sometimes tinnitus (ringing in the ears) can make it more difficult to obtain valid thresholds. If the results are inconsistent, the worker may be having trouble distinguishing the test tone from the ringing in his ears. One option is to refer the worker to an audiologist to obtain a valid test.
One option is to use an interpreter to explain the purpose of the test and instructions. Some audiometers have an additional feature to instruct the worker through the earphones, in the preferred language.
A visual inspection of the ear canal is not required by regulation. However, it can give helpful information about the health of the ear and whether or not a test should be conducted.
IMPORTANT NOTE: This information is based on selected current national requirements. Other country or local requirements may be different. Always consult User Instructions and follow local laws and regulations. This website contains an overview of general information and should not be relied upon to make specific decisions. Reading this information does not certify proficiency in safety and health. Information is current as of the date of publication, and requirements can change in the future. This information should not be relied upon in isolation, as the content is often accompanied by additional and/or clarifying information. All applicable laws and regulations must be followed.