OSHA Letter of Interpretation: Professional Supervisor Requirements Under 1910.95

OSHA Letters of Interpretation have clarified the Professional Supervisor requirements under 1910.95(g)(3). This guide covers what PS qualifications OSHA requires, active review obligations, and the CAOHC certification question. OSHA Letters of Interpretation are the agency's official written clarifications of 29 CFR 1910.95 requirements. According to CDC/NIOSH, approximately 22 million U.S. workers are exposed to hazardous occupational noise annually. Note: This guide reflects OSHA's known compliance positions; always consult current OSHA guidance and legal counsel for specific situations.

Soundtrace is built around OSHA's official compliance positions — including the 2022 boothless audiometry LOI — with per-audiogram ambient noise validation, licensed audiologist Professional Supervisor review, and documentation that satisfies OSHA inspection requirements.

The Professional Supervisor Requirement in 1910.95(g)(3)

OSHA 1910.95(g)(3) requires that audiometric testing 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 demonstrated competence in audiometric technician skills." Further, it requires that audiograms be reviewed by an audiologist, otolaryngologist, or other physician.

What OSHA Interpretations Have Clarified on PS Requirements

CAOHC Certification Is Not Required for Test Administration

OSHA interpretations have clarified that CAOHC certification is one way to demonstrate competence as an audiometric technician but is not the only way. An employer who demonstrates through documented training and performance assessment that a technician has the skills required to administer valid audiometric tests satisfies the "demonstrated competence" standard. CAOHC certification is the most recognized and accepted path because it creates a credential that an OSHA compliance officer can verify, but it is not categorically required.

For Soundtrace's automated microprocessor audiometer, which conducts testing without a human technician, the relevant question is whether the instrument itself — and the process surrounding it — produces valid audiograms under PS supervision. The technology has addressed this through automated self-calibration, ambient noise validation, and PS review of all results.

The PS Must Actually Review Audiograms

OSHA has consistently interpreted 1910.95(g)(3) to require active review by the PS, not nominal association. A PS who is listed on the HCP but does not review individual audiograms, identify STSs, and make referral decisions does not satisfy the requirement. The PS's signature on audiometric records without evidence of actual clinical review has been cited as a violation during inspections.

Timing of PS Review

OSHA requires STS notification within 21 days of determination. The PS's review is what determines the STS. OSHA expects PS review to occur within a reasonable time after testing — not 6 months after the annual audiogram batch is complete. Unreasonable delays in PS review that prevent timely STS notification are treated as violations of the notification requirement.

Practical Compliance Approach

Every hearing conservation program should be able to document: the PS's credentials (license number, certification), the process by which audiograms are transmitted to the PS for review, the turnaround standard for PS review of routine audiograms and potential STSs, and records of PS review with dates. Soundtrace's model: all audiograms are reviewed by Dr. Rivka Strom, a licensed audiologist serving as Professional Supervisor, with review completed and results documented for each employer's program.