Occupational Noise Exposure and Hearing Conservation

Occupational Noise Exposure and Hearing Conservation (29 CFR 1910.95) is the OSHA standard that limits how much workplace noise employees can be exposed to and requires a hearing conservation program when exposures reach an action level. It protects workers from permanent noise-induced hearing loss, which develops gradually and cannot be reversed.

Any general industry employer with loud equipment, such as presses, compressors, saws, grinders or generators, should know where its exposures stand. Once employees reach the action level, the standard brings monitoring, audiometric testing, hearing protection, annual training and recordkeeping duties.

What Is the Occupational Noise Exposure Standard?

29 CFR 1910.95 sits in Subpart G, Occupational Health and Environmental Control, of OSHA's general industry standards. It has two layers:

• The permissible exposure limit (PEL) in 1910.95(a) and (b), which caps noise exposure and requires controls when it is exceeded.
• The hearing conservation program in 1910.95(c) through (n), which applies at a lower action level.

Key terms:

• dBA is sound level in decibels measured on the A-weighted scale at slow response, which approximates how the human ear perceives sound.
• Time-weighted average (TWA) is the average exposure over an 8-hour workday.
• Dose expresses exposure as a percentage of the allowable limit. An 8-hour TWA of 85 dBA equals a 50 percent dose.
• Action level is an 8-hour TWA of 85 dBA, or a dose of 50 percent.
• Standard threshold shift (STS) is a change in hearing threshold, relative to the baseline audiogram, averaging 10 dB or more at 2000, 3000 and 4000 Hz in either ear.

Who Must Comply?

1910.95 applies to general industry employers under federal OSHA jurisdiction. The PEL applies to every covered employer. The hearing conservation program applies when any employee's exposure equals or exceeds the 85 dBA action level.

Under 1910.95(o), paragraphs (c) through (n), the hearing conservation program, do not apply to oil and gas well drilling and servicing operations. Construction employers follow the noise provisions in 29 CFR Part 1926 instead, and OSHA has no specific noise standard for agriculture, where the General Duty Clause can apply. State Plan states must have rules at least as effective as OSHA's and may be stricter.

Key Requirements

Permissible exposure limit, 1910.95(b)

Table G-16 sets the PEL at 90 dBA for an 8-hour day. The allowed time halves for every 5 dB increase: 4 hours at 95 dBA, 2 hours at 100 dBA, 1 hour at 105 dBA and 15 minutes or less at 115 dBA. Impulse or impact noise should not exceed a 140 dB peak sound pressure level.

When exposures exceed the PEL, the employer must use feasible administrative or engineering controls first. If those controls do not bring exposure within the table, hearing protection must be provided and used.

Exposure monitoring, 1910.95(d) through (f)

When information indicates any employee's exposure may equal or exceed the action level, the employer must monitor to identify employees for the program and to help select hearing protectors. Monitoring must integrate all continuous, intermittent and impulsive sound levels from 80 to 130 dB, and instruments must be calibrated.

Monitoring must be repeated whenever a change in production, process, equipment or controls increases exposures enough that more employees reach the action level or that hearing protectors may no longer be adequate. Employees at or above the action level must be notified of the results, and employees or their representatives must be allowed to observe monitoring.

Audiometric testing, 1910.95(g) and (h)

• Testing must be available at no cost to all employees at or above the action level.
• A baseline audiogram is due within 6 months of first exposure at or above the action level. If a mobile test van is used, the employer has up to 1 year, but employees must wear hearing protectors from month 6 until the baseline is done.
• Baseline testing must follow at least 14 hours without workplace noise. Hearing protectors may substitute for this quiet period.
• Annual audiograms are required after the baseline, and each is compared with the baseline to check for an STS.
• If an STS is found, the employee must be notified in writing within 21 days. Unless a physician determines the shift is not work-related or aggravated by noise, the employer must fit or refit hearing protectors, train the employee and require their use, and refer the employee for further evaluation where appropriate.

Tests must be performed by a licensed or certified audiologist, otolaryngologist or other physician, or by a competent technician responsible to one of them. Audiometers need a functional check each day they are used, an acoustic calibration at least annually and an exhaustive calibration at least every two years.

Hearing protectors, 1910.95(i) and (j)

Hearing protectors must be available at no cost to all employees at or above the action level and replaced as needed. They must be worn by employees exposed above the PEL, and by employees at or above the action level who have not yet had a baseline audiogram or who have an STS. Employees must be able to choose from a variety of suitable protectors, and the employer must ensure proper initial fitting and supervise correct use.

Protectors must reduce exposure to at most 90 dBA TWA, or to 85 dBA TWA or below for employees who have had an STS. Attenuation must be evaluated for the specific noise environment, using methods in Appendix B.

Training, 1910.95(k) and (l)

Every employee at or above the action level must take part in a training program, repeated annually and updated as equipment and processes change. Training must cover the effects of noise on hearing; the purpose, advantages, disadvantages and attenuation of different hearing protectors, with instructions on selection, fitting, use and care; and the purpose of audiometric testing and how it works. The employer must post a copy of the standard in the workplace.

Recordkeeping and Retention

• Noise exposure measurements must be kept for 2 years.
• Audiometric test records must be kept for the duration of the affected employee's employment. They must include the employee's name and job classification, the date of the audiogram, the examiner's name, the date of the last acoustic or exhaustive calibration, and the employee's most recent noise exposure assessment.
• Background sound pressure levels in audiometric test rooms must also be recorded.

Separately, under the OSHA recordkeeping rule at 29 CFR 1904.10, a work-related STS must be entered on the OSHA 300 Log when the employee's total hearing level is also 25 dB or more above audiometric zero, averaged at 2000, 3000 and 4000 Hz in the same ear. See OSHA Injury and Illness Recordkeeping for the wider rule.

Common Violations and Penalties

• No exposure monitoring. Employers assume areas are "not that loud" without measuring, or never re-measure after adding equipment.
• Late or missing baselines. New hires work in noisy areas well past the 6-month window without a baseline audiogram.
• Skipped annual audiograms or annual tests that are never compared with the baseline.
• No STS follow-up. Shifts are found but employees are not notified in writing within 21 days or refitted with protection.
• One type of earplug for everyone, with no choice of protectors and no attenuation check.

As of 2026, OSHA's maximum penalties are $16,550 per serious or other-than-serious violation and $165,514 per willful or repeated violation. State Plan amounts may differ.

How to Comply: Step by Step

1. Screen for noise. Identify areas and tasks where people must raise their voices to talk at arm's length, a common sign that exposures may be near the action level.
2. Measure exposures. Use calibrated dosimeters or sound level meters and personal sampling for mobile workers. Record results.
3. Control at the source. Apply engineering controls such as enclosures, mufflers, isolation mounts and maintenance, and administrative controls such as rotating tasks, especially where exposures exceed 90 dBA.
4. Enroll employees at or above 85 dBA. Notify them of results and start the hearing conservation program.
5. Schedule audiometry. Get baselines within 6 months and annual tests after that. Track due dates for each employee.
6. Provide and fit protectors. Offer a choice of earplugs and earmuffs, check attenuation for each environment and supervise use.
7. Train annually. Cover all required topics and keep attendance records.
8. Act on threshold shifts. Notify in writing within 21 days, refit and retrain, and decide whether the case is recordable under 1904.10.
9. Keep records for the required periods and re-monitor when processes change.

How SMS360 Helps

SMS360's Training Management module helps teams keep hearing conservation on schedule. Safety managers can assign annual noise training to employees in enrolled roles, track completion and set expiry reminders so refreshers are not missed. Training records stay in one place, ready to show an inspector.

The same tools can track annual audiogram due dates and store monitoring results, and dashboards show who is overdue so supervisors can follow up.

Frequently Asked Questions

At what noise level is a hearing conservation program required?

OSHA requires a hearing conservation program when employee exposure equals or exceeds an 8-hour time-weighted average of 85 dBA, which is a 50 percent noise dose. The separate permissible exposure limit is 90 dBA for 8 hours, above which feasible engineering or administrative controls are required.

How often are hearing tests required under OSHA?

Employees in the hearing conservation program need a baseline audiogram within 6 months of first exposure at or above the action level, or within 1 year when a mobile test van is used. After the baseline, audiograms are required at least annually and must be compared with the baseline to detect a standard threshold shift.

How long must noise and audiometric records be kept?

Noise exposure measurement records must be kept for 2 years. Audiometric test records must be kept for the duration of the affected employee's employment. Both must be made available to employees, former employees and their representatives on request.

Is a standard threshold shift always recordable on the OSHA 300 Log?

No. Under 1904.10, a work-related standard threshold shift is recordable only when the employee's overall hearing level in the same ear is also 25 dB or more above audiometric zero, averaged at 2000, 3000 and 4000 Hz. Age correction may be used for the shift but not for the 25 dB test.