85 decibels is the exact line where OSHA requires a formal hearing conservation program. The audiogram schedule, why the baseline audiogram matters more than people think, and what triggers the program in the first place.
85 decibels doesn’t sound dramatic on paper, but it’s the exact
line where OSHA requires an employer to start a formal hearing
conservation program — not when someone complains their ears are
ringing, and not at some higher, more obviously dangerous level.
OSHA’s hearing conservation standard, 29 CFR 1910.95, requires a
formal hearing conservation program whenever employee noise exposure
reaches or exceeds an 8-hour time-weighted average (TWA) of 85
decibels — the “action level.” Once a work area crosses that
threshold, the employer has to implement noise monitoring, provide
hearing protectors at no cost with a real choice of options, train
affected employees, and start audiometric testing.
| Test | Timing |
|---|---|
| Baseline audiogram | Within 6 months of first exposure at or above the action level (within 1 year if using a mobile testing van) |
| Annual audiogram | Every year after the baseline is established, for as long as exposure continues |
| Standard threshold shift response | Triggered by a 10-decibel average shift at specific frequencies, requiring enhanced protection and a clinical evaluation referral |
Without a genuine baseline established early — not delayed, not
rushed on someone’s first day before they’re settled in — there’s no
reliable way to detect a standard threshold shift later, since a shift
is measured as change from that specific individual’s own baseline,
not against a generic population norm. A late or sloppy baseline
quietly undermines the entire point of annual testing for that
employee going forward.
Noise monitoring has to actually identify which employees are
exposed at or above the action level — that means monitoring
representative of a worker’s actual daily exposure pattern, not a
single spot reading taken during a quiet moment. Equipment changes, new
processes, or a plant layout change can shift exposure levels enough
to bring workers newly into or out of the program, which is why
monitoring needs to be an ongoing practice rather than a box checked
once and forgotten.
Hearing conservation program administration isn’t a standalone
course in SCMEP’s current catalog — it fits within our broader
safety culture and plant safety event programs.
As a NIST Manufacturing Extension Partnership
affiliate serving South Carolina manufacturers since 1989, our
focus is building daily hearing-protection habits and awareness that
support a compliant program, not replacing certified audiometric
testing services.
If your plant needs to build or strengthen a hearing conservation
program, you can browse the Safety training
catalog or email the training team.
Respirator programs and hearing conservation programs are both exposure-driven OSHA requirements triggered by measurable thresholds. See our related guide on OSHA respiratory protection for how 1910.134 handles the equivalent trigger for airborne hazards.
OSHA requires a hearing conservation program whenever employee noise exposure reaches or exceeds an 8-hour time-weighted average of 85 decibels — the “action level” defined in 29 CFR 1910.95.
A baseline audiogram is required within 6 months of an employee’s first exposure at or above the action level (within 1 year if using a mobile testing van), followed by annual audiograms for as long as exposure continues.
A 10-decibel average change at specific frequencies, measured against an employee’s individual baseline audiogram. It triggers enhanced hearing protection requirements and a referral for clinical evaluation.
A standard threshold shift is measured as change from an individual’s own baseline, not a population average. A late or inaccurate baseline undermines the ability to detect real hearing changes in that employee going forward.
