Audiograms & Hearing Tests
Noise damage builds up quietly: you don't feel it happening. An audiogram is a hearing test that shows how well you hear different pitches. In a hearing conservation program, regular audiograms catch changes early, while there's still time to prevent more loss.
- Noisy Trades
- Manufacturing Workers
- Safety Managers
- Equipment Operators
When employers must test
OSHA's occupational noise standard (29 CFR 1910.95) requires a hearing conservation program when workers' noise exposure is at or above an 8-hour time-weighted average of 85 decibels (dBA), called the action level. In that program, employers must provide audiometric testing at no cost to the employee. Construction has different general rules, but many construction employers follow the same program for noisy work. See Noise and Hearing Protection.
- A baseline audiogram is done within 6 months of an employee's first exposure at or above the action level (within 1 year if a mobile test van is used, with hearing protectors worn from 6 months on).
- An annual audiogram is done at least once each year after the baseline.
- Tests must be run by a licensed or certified audiologist, otolaryngologist or physician, or by a technician certified or trained and supervised by one, with calibrated equipment in a suitable quiet room.
Preparing for the test
- For the baseline, be away from workplace noise for at least 14 hours before the test (hearing protectors can be used to meet this). Follow the same quiet-time instructions for annual tests when your employer gives them.
- Avoid loud off-the-job noise before the test, such as concerts, power tools and shooting.
- Tell the tester about earaches, colds, ear infections, medicines and past hearing problems. Wax in the ear canal can change results.
- Wear no headphones or earbuds before the test.
- During the test, you wear headphones and press a button when you hear soft tones at different pitches. Take your time and respond to the faintest sounds you hear.
Reading the audiogram
- The graph shows your quietest heard level (hearing threshold, in decibels) at each frequency, often from 500 to 8,000 hertz, for each ear. Higher on the chart means better hearing; lower means more loss.
- Noise damage typically shows up first as a “notch” around 3,000 to 6,000 Hz, making it hard to hear consonants like s, f and th, and to follow speech in noise.
- The test compares your current results with your baseline to look for change over time.
Standard threshold shift (STS)
A standard threshold shift is a change in hearing compared with the baseline, averaging 10 decibels or more at 2,000, 3,000 and 4,000 Hz in either ear. The employer must:
- Tell you in writing within 21 days of learning about the shift.
- Make sure you use hearing protectors, or refit and retrain you and give you more effective protectors if you already use them.
- Refer you for further evaluation if needed, and tell you if a medical problem might be caused or aggravated by wearing hearing protectors.
- Record the loss on the OSHA injury and illness log if it is work-related and the shift meets the recording criteria (an average of 10 dB or more shift at 2,000 to 4,000 Hz with total hearing at or above 25 dB above audiometric zero). See OSHA Recordkeeping.
Some shifts are temporary or caused by something other than work, so a retest within 30 days can confirm or cancel the shift. Don't ignore the result: it means your protection isn't working well enough. See Hearing Protection Fit Testing.
Your rights and responsibilities
- The test is free, and held during paid time or at a time and place your employer arranges.
- You can ask for copies of your audiograms and noise exposure records; employers keep audiometric records for the duration of employment. See Access to Records.
- Wear your hearing protection as trained, and tell your employer if it doesn't fit or is uncomfortable.
- Report ringing in the ears (tinnitus), muffled hearing after work, or trouble following conversation. See a doctor.
- You can't be punished for raising noise problems or asking for testing. See Retaliation & Section 11(c).
Hearing test checklist
- I know whether my job is in the hearing conservation program
- I follow quiet-time instructions before my test
- I tell the tester about ear problems and medicines
- I ask for a copy of my results and understand any shift
- I get a better-fitting protector if my hearing changes
Standards & references
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