Audiometer Calibration: What OSHA and ANSI Actually Require
July 6, 2026 · 5 min read
By Jeff Schroeder, Foster Special Instruments
Every audiogram in your hearing conservation file is only as good as the audiometer that produced it. 29 CFR 1910.95 ties audiometric testing to specific calibration requirements, and an inspector can ask for the calibration trail behind any test record. See Foster's audiometer calibration service for what is covered. Foster also offers sound booth testing.
The three layers of audiometer checks
OSHA's Appendix E lays out a three-layer regime:
- Functional (daily) check — test a person with known, stable thresholds before each day's use, and listen for distortion or unwanted sounds
- Acoustic calibration — at least annually, or whenever the functional check shows deviations of 10 dB or more; measures output levels and attenuator linearity against ANSI specifications
- Exhaustive calibration — at least every two years, or when acoustic calibration shows deviations of 15 dB or more; a full workup against the ANSI S3.6 specification
Why the calibration date lives in your employee records
1910.95 requires each employee's audiometric record to include the date of the last acoustic or exhaustive calibration of the audiometer used. If your calibration lapses, every audiogram taken on that instrument carries the lapse with it — which is why the calibration certificate is compliance paperwork, not just service paperwork.
The room matters too: ANSI S3.1 booth requirements
Audiometric test rooms must not exceed the maximum permissible ambient noise levels in the standard. Sound-level certification of your booth or test environment is how you demonstrate it — and it belongs on the same annual service visit as the audiometer calibration.
What a defensible calibration file looks like
For each audiometer: a traceable annual calibration certificate, the functional-check log, and the booth's sound-level certification. For the program: a reminder system so none of the three ever silently lapses.
Foster’s audiometer calibration services cover ANSI S3.6 calibration on industry-standard ACS hardware and software, ANSI S3.1 booth certification, and reminders before every due date. Choose on-site, in-house, or mail-in, whether or not the instrument came from us.
On-site across OH, KY, IN, IL & MI; mail-in nationwide. Traceable certificate with every unit and free loaners during extensive repairs. Schedule calibration.
On-site across OH, KY, IN, IL & MI; mail-in nationwide. Traceable certificate with every unit and free loaners during extensive repairs.
Schedule calibrationRelated guides
Audiometer Calibration Vendor Selection: Questions to Ask First
What to confirm before signing with an audiometer calibration vendor: traceability, certificate contents, turnaround, and the ANSI S3.6 edition they test to.
5 min read Read →Calibration & InstrumentsIn-House vs. Vendor Calibration: What Actually Changes the Math
Building an in-house calibration lab for audiometers and sound equipment looks cheaper on paper. Here is where that math breaks down for most employers.
5 min read Read →Calibration & InstrumentsAudiometer Repair vs. Replace: When to Stop Fixing an Aging Unit
How to decide whether an aging audiometer is worth repairing again, using calibration history, downtime, and ANSI S3.6 compliance risk instead of guesswork.
5 min read Read →