OSHA 29 CFR 1910.95 Appendix F provides age correction tables that allow employers to subtract expected age-related hearing threshold changes from measured annual audiogram shifts before determining whether an STS has occurred. The tables are gender-specific and frequency-specific, covering the 2000, 3000, and 4000 Hz frequencies used in STS calculation. Using Appendix F correctly requires understanding the calculation sequence, when age correction is clinically appropriate, and what the tables do and don’t capture. According to CDC/NIOSH, age-related hearing loss (presbycusis) becomes biologically active in the 50s–70s, making age correction most impactful for employers with aging noise-exposed workforces.
How to Apply Appendix F Age Correction
- Record the worker’s age at the time of the baseline audiogram and at the time of the current annual audiogram
- For each frequency (2000, 3000, 4000 Hz), look up the expected threshold value in the appropriate gender table at both ages
- Subtract the baseline-age table value from the current-age table value to get the expected age-related change at that frequency
- Subtract this expected age-related change from the measured threshold change at each frequency
- Use the age-corrected threshold changes to calculate the 2000/3000/4000 Hz average for STS determination
Appendix F age correction is optional and should reflect clinical judgment about whether the threshold shift reflects primarily age-related change or noise-induced progression. A professional supervisor who always applies age correction reduces apparent STSs across all older workers — potentially masking genuine noise-induced progression. A professional supervisor who never applies age correction may over-identify STSs in older workers with presbycusis-driven shifts. The correct approach is individualized professional judgment based on the worker’s audiometric pattern and exposure history.
What the Tables Do and Don’t Capture
Appendix F tables are derived from studies of non-noise-exposed populations. They capture expected presbycusis — age-related hair cell degeneration that produces high-frequency threshold changes independent of noise exposure. They do not capture:
- Noise-induced component of threshold shift (this is what remains after age correction)
- Individual variation in aging rates (some workers age audiometrically faster or slower than the table averages)
- Disease-related hearing changes (Meniere’s disease, acoustic neuroma, etc.)
- Ototoxic chemical contribution to threshold shift
OSHA’s recordkeeping standard (29 CFR 1904) allows age correction when determining recordability of work-related hearing loss. If age-corrected thresholds do not meet the recordability criteria (10 dB STS plus 25 dB HL combined), the case is not recordable. Consistent application of age correction decisions — documenting when and why it was applied or not applied — protects the employer in OSHA recordkeeping audits.
Frequently Asked Questions
Individualized Age Correction Applied by Licensed Audiologist
Soundtrace Professional Supervisor Dr. Rivka Strom applies Appendix F age correction based on individual clinical judgment — neither uniformly applying nor uniformly skipping it — for accurate STS determinations across aging workforces.
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