OSHA Appendix F: Age Correction Tables for Audiometric Testing

OSHA Appendix F to 29 CFR 1910.95 is a short but frequently misunderstood annex. It provides the age correction tables that employers may optionally apply when calculating standard threshold shifts — and doing so correctly requires understanding what the tables contain, how they are structured, and where they categorically may not be applied. This guide provides a complete reference for Appendix F: what the tables show, how to use them in the STS calculation, and the critical prohibition on their use in 300 Log recordability determinations.

Soundtrace calculates STS both with and without Appendix F age correction for every annual audiogram, providing program coordinators and PLHCP reviewers with both results simultaneously for full compliance visibility.

What Appendix F Contains and Why It Exists

Appendix F to 29 CFR 1910.95 is titled “Audiometric Test Rooms.” Wait — actually, Appendix F is titled “Calculation and Application of Age Correction to Audiograms.” OSHA included it in the hearing conservation standard because of a recognized scientific problem: hearing thresholds change over time due to both noise damage and normal aging (presbycusis), and these two processes are impossible to distinguish on a pure-tone audiogram.

Without age correction, an employer using annual audiometry for STS detection would flag some threshold shifts that are attributable entirely to normal aging rather than noise-induced damage. These shifts would trigger the full STS response protocol — employee notification, HPD refitting, PLHCP referral — for a biological process unrelated to the occupational noise exposure the program is designed to address.

OSHA’s response was to make age correction optional: employers who wish to remove the expected age-related component from observed threshold shifts before computing STS may do so using the Appendix F tables.

How the Appendix F Tables Are Structured

Appendix F contains two tables — one for males and one for females. Each table lists ages from 20 to 60 (and typically includes a 60+ category), with columns for three frequencies: 2000 Hz, 3000 Hz, and 4000 Hz.

The values in each cell represent the expected cumulative threshold elevation in dB HL attributable to age alone at that frequency for a person of that age and sex, relative to audiometric zero. These are not annual change rates — they are cumulative expected values derived from epidemiological data on non-noise-exposed populations.

The tables are used comparatively: the age correction applied to a specific STS calculation is the difference between the Appendix F value at the worker’s current age and the Appendix F value at the worker’s age at the time of the baseline audiogram. This difference represents the expected age-related threshold change over the interval between baseline and current test.

The Appendix F Tables

The values below are from OSHA 29 CFR 1910.95 Appendix F. These represent cumulative expected threshold elevation (dB HL) attributable to age alone, by sex and frequency. The full official tables are available at ecfr.gov.

How to Use the Appendix F Tables in STS Calculations

Applying age correction from Appendix F requires four steps, performed separately for each ear and each of the three STS frequencies:

1. Record the worker’s age at baseline and look up the Appendix F value for that age, sex, and frequency (e.g., male, age 35, 4000 Hz = 6 dB)
2. Record the worker’s age at the current test and look up the Appendix F value for that age, sex, and frequency (e.g., male, age 45, 4000 Hz = 11 dB)
3. Calculate the age adjustment for that frequency: subtract the baseline value from the current value (11 − 6 = 5 dB age adjustment at 4000 Hz)
4. Subtract the age adjustment from the measured threshold shift at that frequency (if the measured 4000 Hz shift is 8 dB, the age-corrected shift is 8 − 5 = 3 dB)

After computing the age-corrected shift at each of the three STS frequencies, average the three results. If the average is 10 dB or greater, an STS has occurred. If less than 10 dB, no STS.

Where Age Correction Is Explicitly Prohibited

OSHA 1904.10 prohibits the use of age correction for 300 Log recordability determinations. The recordability threshold — 25 dB average hearing level at 2000, 3000, and 4000 Hz — is measured from audiometric zero without adjustment. This prohibition is explicit, firm, and has no exception.

This creates a situation that confuses some employers: the same audiometric data may require two separate calculations using different methods. The STS calculation may use age correction (if the employer’s program policy applies it); the recordability calculation must not use age correction regardless of what the STS policy is.

Handling Zero and Negative Age-Corrected Results

The Appendix F age correction procedure can produce unusual results at the frequency level when the age adjustment is larger than the measured shift. For example, if the measured shift at 2000 Hz is 3 dB but the age adjustment at 2000 Hz is 5 dB, the arithmetic produces a −2 dB corrected shift.

OSHA’s intended handling is to use zero for that frequency in the average — a negative corrected shift is treated as zero. Age correction cannot produce a “better than baseline” result for any frequency. If the corrected value at a frequency is negative, substitute zero before averaging.

▶ Bottom line: The minimum corrected shift at any frequency is zero. Negative corrected values are floored to zero before averaging the three STS frequencies.

Setting a Consistent Program Policy

OSHA does not require programs to decide in advance whether to use Appendix F age correction — but consistency is essential. Selectively applying age correction when it benefits the employer and not applying it otherwise is an indefensible program practice. The program policy should:

• Specify whether age correction will be applied to all STS calculations or none
• State that 300 Log recordability evaluations will never use age correction
• Track both corrected and uncorrected results as a best practice, regardless of which governs the official STS determination
• Be documented in the written hearing conservation program

Frequently asked questions