How to Start an In-House Hearing Conservation Program

Bringing audiometric testing in-house gives you control over scheduling, faster baselines for new hires, on-time retests, and one place for every employee's hearing history. It also means your organization takes on responsibility for doing each step the way OSHA 29 CFR 1910.95 requires.

This guide lays out the steps in the order you'll actually do them. If you're still deciding whether in-house testing makes financial sense, start with our mobile van vs. in-house cost comparison.

Step 1: Confirm who needs to be in the program

A hearing conservation program is required for employees whose noise exposure equals or exceeds an 8-hour time-weighted average of 85 dBA — the action level. Before you buy anything, you need current noise monitoring data that tells you who those employees are.

• Area and personal monitoring: Use sound level meters and noise dosimeters to identify exposed jobs and areas.
• Repeat when things change: OSHA requires monitoring to be repeated when changes in production, process, equipment, or controls increase exposures.
• Notify employees: Employees exposed at or above the action level must be notified of the monitoring results.
• Keep the records: Noise exposure measurement records must be kept for at least two years.

Your monitoring results give you the headcount that drives every other decision: how many baselines and annuals you'll run per year, how much test capacity you need, and whether one site or several need their own setup.

Step 2: Train and certify your tester

OSHA requires audiometric tests to be performed by a licensed or certified audiologist, otolaryngologist, or other physician, or by a technician who is certified by the Council for Accreditation in Occupational Hearing Conservation (CAOHC) or who has satisfactorily demonstrated competence in administering audiometric exams. A technician must be responsible to an audiologist, otolaryngologist, or physician.

In practice, most in-house programs send one or two employees through a CAOHC course. It's roughly 20 hours, taught by a CAOHC-certified Course Director, and the certification is valid for five years. Train at least two people if you can, so vacations and turnover don't stall testing. Our CAOHC certification guide covers the process in detail.

At the same time, line up your professional supervisor — the audiologist, otolaryngologist, or physician who will be responsible for the technician, review problem audiograms, and decide on referrals. Many employers contract this role.

Step 3: Set up a test space that meets Appendix D

Audiometric tests must be conducted in a room meeting the maximum allowable octave-band sound pressure levels in Appendix D of 1910.95. Background noise that exceeds these limits can make thresholds look worse than they are — which corrupts baselines and creates false shifts later.

You have two options:

• A prefabricated audiometric test booth. The most reliable way to meet Appendix D in a noisy facility. Prices vary by size and rating; roughly $3,000–$15,000 or more is a typical range, but get quotes.
• An existing quiet room. Some offices or interior rooms already meet the limits, especially away from production areas and HVAC equipment. You'll need octave-band measurements at the test location, during the times you'll actually test, to confirm it.

Whichever you choose, measure it, document the result, and re-measure if the environment changes (new equipment next door, a relocated compressor, a different shift pattern).

Step 4: Choose an ANSI S3.6 audiometer and set up calibration

OSHA's Appendix C requires audiometers that meet the specifications of ANSI S3.6. That can be a traditional desktop audiometer or a digital audiometer. What matters most for an in-house program:

• Required frequencies: The audiometer must test 500, 1000, 2000, 3000, 4000, and 6000 Hz in each ear.
• How results get recorded: Paper or local files create transcription errors and scattered records. An audiometer that sends results directly into your records system removes that step.
• Portability: If you test at more than one site, a portable unit such as an iPad audiometer can move with the tester — as long as each location meets Appendix D.

Calibration requirements come from Appendix E:

• Functional check before each day's use: Test a person with known, stable hearing and listen for distortion or unwanted sound. Record it.
• Acoustic calibration at least annually.
• Exhaustive calibration at least every two years.

Schedule calibration on a fixed date, and keep certificates with your program records — the date of the audiometer's last acoustic or exhaustive calibration is part of each audiometric test record.

Step 5: Establish valid baselines

The baseline audiogram is the reference every future test is compared to, so it has to be right. OSHA requires a valid baseline within 6 months of an employee's first exposure at or above the action level. (Where a mobile test van is used, the employer has up to one year, but employees must wear hearing protection after 6 months until the baseline is obtained. With in-house testing, you'll normally be well inside 6 months.)

• 14 hours of quiet first: Baseline testing must be preceded by at least 14 hours without exposure to workplace noise. Hearing protectors may be used to meet this requirement.
• Notify employees in advance to avoid high levels of non-occupational noise during that period.
• Test new hires early. The first week on the job is ideal.

For the details that trip programs up, see baseline audiogram best practices.

Step 6: Run annual audiograms

Every employee in the program needs a new audiogram at least annually after the baseline. In-house programs have the advantage here: you can spread testing across the year instead of cramming it into a single van day.

• Schedule by anniversary month so tester workload stays even.
• Test every shift during its own hours.
• Track who's due. An overdue list you check weekly is simpler than chasing stragglers in December.

Step 7: Compare to baseline and act on shifts

Each annual audiogram must be compared to the baseline to determine whether a standard threshold shift (STS) has occurred — an average change of 10 dB or more at 2000, 3000, and 4000 Hz in either ear. OSHA allows age correction using Appendix F. The full method is in our STS calculation guide.

When an STS is found:

• Optional retest within 30 days. You may retest and use the retest result as the annual audiogram.
• Written notification within 21 days of the determination.
• Hearing protection follow-up: Employees not using hearing protectors must be fitted, trained, and required to use them; employees already using them must be refitted and retrained, with protectors offering greater attenuation if needed.
• Referral where indicated for further audiological or otological evaluation, as determined by the reviewing professional.
• Check recordability on the OSHA 300 log.

Problem audiograms go to your audiologist, otolaryngologist, or physician for review. Build this step into your workflow so reviews don't sit in someone's inbox.

Step 8: Keep records you can actually find

OSHA requires you to keep audiometric test records for the duration of the affected employee's employment. Each record must include the employee's name and job classification, the date of the audiogram, the examiner's name, the date of the audiometer's last acoustic or exhaustive calibration, the employee's most recent noise exposure assessment, and background sound pressure level measurements in the test room.

Noise exposure measurement records must be kept for two years. Employees, former employees, their representatives, and OSHA must be given access on request.

This is where many in-house programs struggle — not with testing, but with finding a five-year history for one person on the day an inspector or employee asks.

Common mistakes when starting out

• Testing before the room is measured. Baselines taken in a room that doesn't meet Appendix D can be falsely elevated, hiding real shifts for years. Measure first, then test.
• Skipping the daily functional check on busy days. It takes minutes, and it's the first thing an auditor will ask to see.
• Letting calibration dates drift. An audiometer that's a month past its annual acoustic calibration puts every test in that window in question.
• Relying on one tester. If that person leaves, the program stops until someone else is trained.
• Mixing old vendor records with new in-house tests without a plan. Decide which audiogram is each employee's valid baseline before you start comparing, and bring historical results into the same system.
• No owner for follow-up. STS notifications have a 21-day clock. Someone specific has to own it.

A quick in-house program checklist

• Current noise monitoring identifying employees at or above 85 dBA TWA
• At least one CAOHC-certified (or otherwise qualified) tester, with a named professional supervisor
• Test room or booth measured and documented against Appendix D
• ANSI S3.6 audiometer with daily checks, annual acoustic, and biennial exhaustive calibration on file
• Baseline process for new hires within 6 months, with 14 hours of prior quiet
• Annual testing schedule covering every shift
• STS review, retest, 21-day notification, and referral workflow
• Records retained for the duration of employment

Where AudiVault helps

AudiVault pairs an iPad audiometer built to ANSI S3.6-2025 audiometer specifications with a cloud hearing conservation platform. Tests sync directly to the cloud — no transcription — where each result is compared to the employee's baseline, STS is detected automatically with OSHA age correction, and determination letters are routed to a physician for electronic signature. Every change is written to an audit trail, and results from other audiometers can be imported via CSV.

Wondering whether it pays off for your headcount? Try the in-house hearing testing cost calculator, or review the full OSHA hearing conservation guidelines.