Microprocessor audiometers have fundamentally changed the scalability of occupational audiometric testing. Unlike manual audiometry requiring a licensed clinician at the controls of every test, automated microprocessor audiometers present tones, track responses, and determine thresholds systematically — enabling audiometric testing at the employer’s facility without per-test clinician involvement. OSHA 29 CFR 1910.95 accepts microprocessor audiometry when the audiometer meets ANSI S3.6 standards and results are reviewed by a professional supervisor. According to CDC/NIOSH, approximately 22 million U.S. workers require annual occupational audiometric surveillance.
Microprocessor vs. Manual Audiometry: Key Differences
| Characteristic | Microprocessor Audiometry | Manual Audiometry |
|---|---|---|
| Tone presentation | Automated per programmed protocol | Clinician-controlled |
| Threshold determination | Automated by algorithm | Clinician judgment |
| Test administration | Worker interacts with audiometer directly | Clinician present during test |
| Scalability | High — no per-test clinician involvement | Limited by clinician availability |
| ANSI S3.6 compliance | Yes, if audiometer is properly calibrated | Yes, if audiometer is properly calibrated |
| Professional Supervisor | Required to review results | Required to review results (may be the clinician) |
| OSHA acceptability | Yes, with ANSI S3.6 compliant audiometer | Yes |
Automated microprocessor audiometry eliminates the need for a clinician to be present during each test, but it does not eliminate the Professional Supervisor requirement. A licensed audiologist or physician must review every audiometric result, make STS determinations, and authorize any required follow-up actions. Microprocessor audiometry automates the test administration workflow; the Professional Supervisor handles the clinical interpretation workflow. Both are required for OSHA compliance.
Soundtrace Type 4 Microprocessor Audiometer
Soundtrace uses a Type 4 automated microprocessor audiometer meeting ANSI S3.6 calibration and performance standards. Workers perform the test by responding to automated tone presentations through a simple response interface. Results are immediately transmitted to Soundtrace’s SOC 2 certified, HIPAA-compliant cloud platform for review by Dr. Rivka Strom, Soundtrace’s licensed Supervising Audiologist, or another qualified Professional Supervisor. All STS determinations, age correction applications, and required follow-up documentation are handled by the Professional Supervisor.
The ANSI S3.1-1999 maximum permissible ambient noise level requirements for audiometric test environments apply to microprocessor audiometric testing the same as to manual audiometric testing. An automated audiometer deployed in a test room that does not meet ANSI S3.1-1999 MPANLs produces invalid results regardless of the audiometer’s ANSI S3.6 calibration status. The October 11, 2022 OSHA letter of interpretation confirms that ANSI S3.1-1999 (R2018) MPANLs satisfy OSHA Appendix D requirements.
Frequently Asked Questions
ANSI S3.6-Compliant Automated Audiometry at Employer Facilities
Soundtrace Type 4 microprocessor audiometry deploys at your facility — ANSI S3.6 calibrated, ANSI S3.1-1999 environment compliant, with licensed audiologist Professional Supervisor review of every result.
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