Choosing a Mobile Hearing Testing Vendor: A Compliance Checklist

A safety manager comparing mobile hearing testing vendors usually gets quotes that look nearly identical: a price per employee, a van on-site date, and a promise of "OSHA-compliant" testing. The quote rarely says who performs the test, how the audiometer was last calibrated, or how fast the results reach the person who has to act on a shift. Those details decide whether the program survives an audit, not the price per head.

Foster Special Instruments runs mobile hearing testing. We get asked "what should we be checking before we sign" often enough that it's worth writing down. The answer is the same five items every time: technician credentials, equipment calibration records, the test environment, the data pipeline back to the employer, and who actually reviews a shift.

What credential should the technician have?

29 CFR 1910.95(g)(3) allows a licensed or certified audiologist, otolaryngologist, or other physician, a CAOHC-certified technician, or a technician who has demonstrated competence. Every technician who performs audiometric tests must be responsible to an audiologist, otolaryngologist or physician. A technician who operates microprocessor audiometers does not need to be certified. Some state plans are stricter on who can run the test. In Oregon (OAR 437-002-0095) and Washington (WAC 296-817-20030), a technician who performs audiometric tests must be CAOHC-certified, so the federal demonstrated-competence route is not available there. Ask the vendor for the technician's current Council for Accreditation in Occupational Hearing Conservation (CAOHC) card (it expires every five years) and for the audiologist, otolaryngologist, or physician the technician is responsible to.

How is the audiometer's calibration documented?

A mobile unit's audiometer has the same three OSHA checks as a fixed-booth instrument. Under 29 CFR 1910.95(h)(5)(i), its functional operation is checked before each day's use; (h)(5)(ii) requires an acoustic calibration check at least annually under Appendix E; and (h)(5)(iii) requires an exhaustive calibration at least every two years to ANSI S3.6-1969. Ask for the calibration certificate on the specific unit that will show up, not a generic fleet statement, and check its dates against those intervals. An audiometer that has not been recalibrated on schedule produces results that will not hold up if an employee disputes a standard threshold shift finding later.

Does the test environment meet Appendix D, booth or not?

OSHA does not require a soundproof booth. It requires a test room that meets Appendix D, with background levels recorded. A vendor testing in an open warehouse corner without recording those levels is a liability, whether or not they own a booth. Ask whether the vendor records background levels for the test room, and what they do when a location fails that check (reschedule, relocate, or use a sound-attenuating booth brought along for the day).

How fast do results come back, and in what format?

A completed audiogram that sits in a vendor's system for three weeks does not help a safety manager who needs to know about a standard threshold shift before the employee's next noisy shift. Ask for a written turnaround commitment and ask to see a sample report: does it flag STS and recordable cases explicitly, or does it hand over raw numbers and expect the employer to do the math? Vendors vary widely here, and the format difference is the gap between a program that catches problems early and one that discovers them at the next OSHA inspection.

Who owns the baseline, and what happens with new hires?

A 1984 OSHA interpretation letter, written about the standard's original compliance date, said a company that had only contracted for mobile van testing by the deadline, with the baselines completed after it, would not have complied. The deadline is met by a completed baseline, not a signed contract. The baseline is due within 6 months of an employee's first exposure at or above the action level (1910.95(g)(5)(i)). Where mobile test vans are used, the window is 1 year, with hearing protectors worn for any period beyond 6 months until the baseline is obtained (1910.95(g)(5)(ii)). Ask how the vendor tracks new-hire baseline windows across multiple visit dates, not just the annual retest list.

How Foster handles this

Every Foster mobile hearing test is run by a CAOHC-certified or demonstrated-competence technician under our review process, on an audiometer carrying a current ANSI S3.6 calibration certificate, in a test room that meets Appendix D, with background levels recorded. Results come back with STS and OSHA-recordable cases flagged explicitly, and new-hire baselines are tracked separately from the annual retest schedule so nobody falls outside the baseline window. For employers juggling that schedule across audiometric, fit testing, and BAT training renewal dates on different clocks, Foster's compliance workspace product tracks each employee against the applicable rule and due date in one view rather than three spreadsheets.

Related reading: see our mobile audiometric testing equipment checklist for what should be on the van itself, and our note on results review and notification timelines for what a good turnaround SLA looks like in practice. Foster also runs on-site occupational health testing that combines hearing, spirometry, and fit testing in one visit; request a quote for your site.

FAQ

Does OSHA require a sound-isolating booth for mobile hearing tests?

No. OSHA requires a test room that meets Appendix D of 29 CFR 1910.95, with background levels recorded, not a sound-isolating booth.

Is CAOHC certification legally required for a hearing test technician?

Federally, no. 29 CFR 1910.95(g)(3) allows a licensed or certified audiologist, otolaryngologist, or other physician, a CAOHC-certified technician, or a technician who has demonstrated competence. Every technician who performs audiometric tests must be responsible to an audiologist, otolaryngologist or physician. A technician who operates microprocessor audiometers does not need to be certified. Some state plans are stricter on who can run the test. In Oregon (OAR 437-002-0095) and Washington (WAC 296-817-20030), a technician who performs audiometric tests must be CAOHC-certified, so the federal demonstrated-competence route is not available there.

Can we sign a vendor contract to cover a baseline-audiogram deadline that's about to pass?

No. A 1984 OSHA interpretation letter, written about the standard's original compliance date, said a company that had only contracted for mobile van testing by the deadline, with the baselines completed after it, would not have complied. The deadline is met by a completed baseline, not a signed contract. The baseline is due within 6 months of an employee's first exposure at or above the action level (1910.95(g)(5)(i)). Where mobile test vans are used, the window is 1 year, with hearing protectors worn for any period beyond 6 months until the baseline is obtained (1910.95(g)(5)(ii)).

How often should the mobile unit's audiometer be recalibrated?

OSHA sets the minimums in 29 CFR 1910.95(h)(5): a functional check before each day's use, an acoustic calibration check at least annually under Appendix E, and an exhaustive calibration at least every two years to ANSI S3.6-1969. Ask any vendor for the current calibration certificate on the specific unit being deployed to your site.

Sources

• 29 CFR 1910.95 - Occupational noise exposure (OSHA)
• OSHA interpretation letter, February 3, 1984, written about the standard's original compliance date: a company that had only contracted for mobile van testing by the deadline, with the baselines completed after it, would not have complied
• CAOHC - Occupational Hearing Conservationist FAQ