OSHA hearing conservation and audiometric testing

Under federal OSHA's 29 CFR 1910.95, a general-industry employer must run a continuing, effective hearing conservation programme when employee exposure reaches an 8-hour time-weighted average (TWA) of 85 dBA or a 50% noise dose. That is the action level for the programme. It is not the same as the 90 dBA permissible exposure limit, and it should not be assessed after subtracting the assumed protection of earplugs. Once an employee is included, the employer needs a monitoring basis, baseline and annual audiograms, evaluation of changes, training, suitable protection and records.

The key operational question is not merely “Did we book a hearing test?” It is whether each exposed employee entered the programme at the right time, received a valid baseline, completed annual comparison and received required follow-up when a standard threshold shift was identified. This guide addresses the federal general-industry rule. Construction, maritime work and OSHA-approved State Plans may use different provisions or additional requirements. Identify the governing regime for the actual worksite before copying this schedule.

Start with exposure, not the machinery label

Section 1910.95(c) defines the hearing-conservation action level as an eight-hour TWA of 85 dBA, calculated without credit for hearing-protector attenuation. If information indicates that an employee's exposure may reach the action level, paragraph (d) requires an exposure-monitoring programme. A machine manufacturer's sound rating or one area reading may not describe the worker's actual shift. The monitoring approach must identify workers for inclusion and support protector selection; representative personal sampling is needed in the circumstances the rule describes, such as high mobility or substantial variation in sound levels, unless equivalent area results can be shown.

Create a register of roles and workers assessed, tasks, shifts, noise measurements, sampling method, results and the date monitoring was reviewed. When a production, process, equipment or control change could increase exposure enough to add workers at or above the action level or make protection inadequate, paragraph (d) calls for repeat monitoring. A line extension or a change in time spent near a press can alter exposure even where no new machine is installed.

The action level triggers the programme; it does not mean the employer can ignore higher exposures. The standard separately sets permissible exposure and control requirements in paragraph (b). Industrial hygienists or other competent specialists should evaluate exposure data and controls. This article does not infer an individual employee's eight-hour TWA from a handheld reading.

Establish a valid baseline audiogram

For each employee whose exposure is at or above the action level, paragraph (g)(5) normally requires a valid baseline audiogram within six months of first exposure. A mobile-test-van exception permits up to one year, but if the baseline is obtained more than six months after first exposure, hearing protectors must be worn for the period beyond six months until the baseline is obtained. Do not describe the one-year route as the ordinary rule for every provider.

Baseline testing must be preceded by at least 14 hours without workplace-noise exposure; the regulation permits hearing protectors as a substitute for this quiet period. The employer must also notify employees to avoid high non-occupational noise during the immediately preceding 14 hours. Record the exposure start date, baseline deadline, test appointment, whether the mobile-van exception is used, preparation notice and valid result. A scheduled appointment is not a completed baseline. If a test cannot be validated, resolve that with the qualified test provider rather than silently entering an invalid audiogram as the baseline.

Audiometric tests must be conducted by the qualified people and with the equipment, frequencies, room conditions and calibration practices required by paragraphs (g) and (h). The employer may contract the testing, but remains responsible for the programme. Vendor booking and the worker's participation do not relieve the employer of evaluating the resulting audiogram and following up. Ensure the provider can supply the data needed for comparison and retention rather than only a one-line “pass” label.

Compare annual audiograms to the baseline

Paragraph (g)(6) requires a new audiogram at least annually after the baseline for each employee exposed at or above the 85 dBA action level. The annual result is compared with the employee's baseline to decide whether it is valid and whether a standard threshold shift (STS) occurred. The regulation defines STS as an average change of at least 10 dB at 2,000, 3,000 and 4,000 Hz in either ear, with an allowed age-correction method. A technician may compare tests, but problem audiograms require review by an audiologist, otolaryngologist or physician as the rule states.

The annual record should identify the employee, baseline used, new test date, comparison outcome and any professional review. A company should not automatically reset the baseline each year just to make changes disappear. Paragraph (g)(9) allows a revised baseline under specified circumstances in the judgement of the evaluating clinician. Retain a traceable history of what was used and why. If an employee moved departments, relate the audiogram to the exposure history rather than assuming the new role erased an earlier programme duty.

If an annual audiogram indicates STS, paragraph (g)(7) permits a retest within 30 days and use of that result as the annual audiogram. This is an option, not a licence to leave an apparent shift unresolved. The employer should identify the initial finding, whether a timely retest was chosen, and the final interpretation. Treat a possible STS as a real follow-up workflow with a named owner.

What happens after a standard threshold shift?

If the comparison shows an STS, paragraph (g)(8) requires written notice to the employee within 21 days of the determination. Unless a physician determines the shift is not work related or not aggravated by occupational noise exposure, the employer must take further steps. Employees not using hearing protectors must be fitted, trained and required to use them. Employees already using protectors must be refitted and retrained and given greater attenuation if needed. The rule also provides for clinical audiological or otological referral when the stated conditions call for it.

The employer's follow-up record should separate the clinical interpretation, notice date, protective-equipment action, any referral and completion. “STS detected” in a spreadsheet is not the same as notifying the employee and changing protection where required. Keep sensitive medical detail accessible only to people with a legitimate role; provide operational managers the action they need without broadcasting the whole audiogram.

An STS under the hearing-conservation standard and an OSHA recordable hearing-loss case are not identical decisions. Recordability has its own criteria under Part 1904. Do not mark every STS recordable or assume that no Part 1904 review is needed. Have a qualified reviewer assess the actual result and current recording rule.

Protection, training and workplace controls

At the 85 dBA action level, paragraph (i) requires employers to make hearing protectors available at no cost and replace them when necessary. The rule specifies situations in which wearing them is required, including certain employees without a baseline and those with an STS. Employees must be offered a variety of suitable protectors; the employer must ensure proper initial fit and supervise correct use. A high nominal attenuation number on a box is not proof that protection works for a particular worker and noise environment.

Paragraph (k) requires training for included employees, repeated annually and updated for changes in equipment and work processes. It covers noise effects, the purpose and use of hearing protectors and the reason for audiometric testing. A signature sheet is useful evidence of attendance, but the employer should also ensure that workers understand what they were taught. Where engineering or administrative controls are feasible for exposures addressed by paragraph (b), do not substitute earplugs for the entire control strategy.

Records and retention

Under paragraph (m), maintain accurate exposure-measurement and audiometric-test records. The audiogram record includes employee name and job classification, test date, examiner, relevant calibration date and most recent noise assessment. The rule also addresses test-room background measurements. Retain required noise-exposure measurements for two years and audiometric-test records for the duration of the affected employee's employment. Separate privacy and access controls should be considered; do not place individual audiograms in a shared shift folder.

A working evidence register can link exposure monitoring to inclusion date, baseline due date and result, each annual test, STS interpretation, employee notice, hearing-protector changes, training and retention. Label the record source and reviewer. A missed baseline or an unresolved STS should remain visible until closed; an appointment entry alone should not turn the status green. Preserve records when providers change and verify that historical audiograms can be exported or retrieved in full. These are prudent process suggestions, not extra fields mandated verbatim by the federal rule.

Example: a new fabrication line

A manufacturer starts a cutting line in February. Representative monitoring indicates several operators at or above the 85 dBA action level. The employer identifies the employees and their first exposure dates, implements the hearing-conservation programme, makes hearing protectors available, gives required training and arranges baseline audiograms within the applicable window. Later, a change in production speed increases noise; the employer repeats monitoring and checks whether more employees must be included or different protection is needed. Annual tests are compared to each person's baseline. If an STS is determined, the employee receives written notice and the required follow-up proceeds. Each step has a source record and date. That trail answers a more useful question than “We have hearing tests on file.”

The existing written safety programme guide covers the broader safety-system context. This article owns the specific 1910.95 testing and follow-up task. For a discussion of actual safety-record workflows, visit Complys US OSHA compliance software and request a demonstration. It does not claim Complys measures noise, interprets audiograms, makes STS or recordability decisions, delivers medical services, or automatically applies State Plan law.

Primary source and publication gate

• OSHA 29 CFR 1910.95: action level, monitoring, audiograms, follow-up, protection, training and records.
• OSHA hearing-conservation topic: agency context; the regulation is controlling.

Before publication: check the current federal standard, State Plan applicability, exact owner and product implementation. For an individual audiogram or exposure assessment, use qualified occupational-health professionals and the current rule.

For the related Complys product, see OSHA Compliance Software. This guide is general information, not legal advice; verify current requirements against the official sources linked above.