Audiometer Calibration: What OSHA and ANSI Actually Require

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 calibrates audiometers to ANSI S3.6 on industry-standard ACS hardware and software, certifies booths to ANSI S3.1, and sends reminders before every due date — on-site, in-house, or mail-in, whether or not the instrument came from us.