Under OSHA's audiometric testing requirements in 29 CFR 1910.95(g)(3), the hearing tests in a hearing conservation program must be performed by a licensed or certified audiologist, an otolaryngologist or other physician, or by a technician who is CAOHC-certified or who has satisfactorily demonstrated competence.
Any technician must be responsible to an audiologist, otolaryngologist or physician — and technicians who operate microprocessor audiometers do not need certification.
The technician rule
OSHA's audiometric testing requirements live in the hearing conservation standard, 29 CFR 1910.95, and they apply once a covered program exists.
OSHA requires that program whenever employee noise exposure equals or exceeds an 8-hour time-weighted average of 85 dBA — a 50% dose — the level the rule calls the action level.
Section (g)(3) then fixes who may perform the tests.
The list has three entries:
- a licensed or certified audiologist;
- an otolaryngologist or other physician; or
- a technician who is certified by CAOHC or who has satisfactorily demonstrated competence in administering audiometric examinations.
The same clause adds the supervision rule: a technician who performs audiometric tests must be responsible to an audiologist, otolaryngologist or physician.
That responsibility exists whether or not the technician holds a credential.
OSHA also writes one exemption into the rule: a technician who operates a microprocessor audiometer does not need to be certified.
The exemption removes the certification question, not the supervision one — that technician still answers to a licensed professional.
OSHA is not always the whole rule
CAOHC certification vs demonstrated competence
The two technician routes are not equal in paperwork.
CAOHC certification is a documented credential: a minimum of 20 hours of instruction plus a national exam, with renewal every 5 years.
Demonstrated competence has no course, hour count or exam named in the regulation — the rule states the standard ("satisfactorily demonstrated competence") without prescribing how it is shown.
CAOHC itself states that certification is not mandatory under OSHA.
What it documents, in CAOHC's framing, is proof that a technician has met a high standard of training — that 20-hour minimum plus the national exam.
The credential carries a scope limit that lines up with OSHA's own test battery: COHC training qualifies a person to perform pure-tone air-conduction testing only.
Bone conduction testing and speech audiometry sit outside the credential unless the holder is also a licensed audiologist or physician.
How a competency-demonstrated technician documents that competence is a question to settle with the supervising professional and the employer before testing starts — the regulation does not do it for you.
Mining runs under a stricter definition.
MSHA requires tests to be conducted by a physician or an audiologist, or by a qualified technician under their direction or supervision — and MSHA defines a qualified technician as one certified by CAOHC or by another recognized organization offering equivalent certification.
That definition is certification-based, without the either/or OSHA uses.
For the credential itself — courses, exams, formats, cost and renewal — see CAOHC certification.
Supervision by an audiologist or physician
The supervision clause is one sentence: "A technician who performs audiometric tests must be responsible to an audiologist, otolaryngologist or physician."
It applies to every technician — CAOHC-certified, competency-demonstrated, or running a microprocessor audiometer.
In hearing conservation work, that supervising professional is the program's professional supervisor.
CAOHC describes the role this way: the audiologist, otolaryngologist or physician overseeing the audiometric program has the responsibility to determine the work-relatedness of a hearing loss for recording on the OSHA 300 Log.
CAOHC's credential for that role, the Certified Professional Supervisor of the Audiometric Monitoring Program (CPS/A), is open only to audiologists and physicians with a current practitioner license.
Other professionals may take the course but cannot sit the exam.
The division of labor is the job design to understand before you take a technician role.
The technician performs the tests; the professional supervisor carries the program's clinical determinations, including the work-relatedness call behind an OSHA 300 Log entry.
Audiometer calibration requirements
Calibration runs on three intervals under 29 CFR 1910.95.
A functional check is performed before each day's use.
The audiometer is checked acoustically at least annually.
An exhaustive calibration is performed at least every two years.
The acoustic check carries a threshold: when it shows a deviation of 15 dB or greater, an exhaustive calibration is required.
The daily functional check is technician work.
CAOHC's scope of practice for the COHC makes the certified technician responsible for the daily audiometer functional check, so on a credentialed team that check belongs to the COHC.
Audiogram review and referral
Not every audiogram ends at the technician.
OSHA requires the audiologist, otolaryngologist or physician to review problem audiograms and determine whether there is a need for further evaluation.
The shift with defined consequences in the rule is the standard threshold shift (STS): an average change of 10 dB or more at 2000, 3000 and 4000 Hz in either ear, relative to the baseline, with age correction allowed.
When an STS is determined, the employee must be informed in writing within 21 days of the determination.
CAOHC's scope puts that duty on the certified technician as well: the COHC must ensure employees are notified in writing within 21 days after identifying an STS.
Referral decisions — whether a case needs further evaluation — belong to the reviewing professional, not the technician.
A technician's part is to run the test to the standard, identify the shift and route the audiogram to the reviewing professional.
Who must be tested
Testing attaches to exposure, not to job titles.
OSHA requires a hearing conservation program whenever employee noise exposure equals or exceeds an 8-hour TWA of 85 dBA — the action level, equivalent to a 50% dose.
That exposure line defines the testing population: the rule's annual requirement covers each employee exposed at or above an 85 dBA TWA.
A technician building a testing schedule starts from the employer's noise exposure data, not from a headcount of the whole site.
Audiometric testing is one element of the hearing conservation program; this page covers the testing rules, not the program's other requirements.
The role that owns this testing work day to day is the hearing conservationist — the hearing conservationist career guide covers the job, its employers and its settings.
Baseline audiogram timing and the quiet period
OSHA requires a valid baseline audiogram within 6 months of an employee's first exposure at or above the action level.
When mobile test vans are used, the window extends to within 1 year — a timing difference that shapes van-based programs and the mobile hearing testing technician route.
Validity starts with quiet.
Testing to establish a baseline must be preceded by at least 14 hours without exposure to workplace noise, and hearing protectors may substitute for the quiet period.
For whoever builds the testing calendar, that noise-free window is the constraint that decides when a baseline can happen.
The van extension carries a condition: where a van program obtains the baseline after 6 months, the employee must wear hearing protection until it is obtained.
Annual audiograms
After the baseline, the cadence is fixed: OSHA requires a new audiogram at least annually for each employee exposed at or above an 85 dBA TWA.
The annual test is what makes shift detection possible.
Each year's thresholds are compared against the baseline under the STS definition — the 10 dB average change at 2000, 3000 and 4000 Hz — and a determined shift starts the 21-day written-notification clock.
"At least annually" sets the minimum.
A program can test more often, but every covered employee has to reach the annual threshold for the schedule to meet the rule.
Test frequencies and the test environment
OSHA audiometric tests are pure-tone, air-conduction threshold tests.
The frequencies that must be included, at a minimum, are 500, 1000, 2000, 3000, 4000 and 6000 Hz, and each frequency is tested separately for each ear.
That battery is also the only testing the COHC credential covers.
Testing beyond pure-tone air conduction — bone conduction, speech audiometry — is not COHC work; CAOHC reserves it for people who are also licensed audiologists or physicians.
On the environment itself, the rules covered here are the pre-baseline quiet window and the calibration schedule.
Our research did not confirm the standard's specifications for a testing room or booth, so read 29 CFR 1910.95 directly — or confirm with OSHA — before you set up, buy or audit a test space.
Records you keep
Two retention rules cover the program's paperwork.
Audiometric test records are retained for the duration of the affected employee's employment.
Noise exposure measurement records are retained for 2 years.
The split matters in practice.
An employee's audiometric file is a per-employee record, kept for as long as the employee is employed, that accumulates every annual test, while exposure measurements have a fixed 2-year life.
For a technician, the audiometric record is the file every test adds to — which is why threshold accuracy on a single visit carries through an entire employment period.
Career information, not licensing, legal, medical, clinical, billing or coding advice. Confirm the current requirements with OSHA and 29 CFR 1910.95, and with your state's labor or health agency, before you run or rely on an audiometric testing program.