What OSHA's hearing conservation program requires of you

This page explains what the rules and common practice call for. Every site is different, and what a survey or a filing needs at your facility is something we work out with you after we see it.

The trigger is an 8-hour time-weighted average (TWA) of 85 decibels (dBA), which is a 50% noise dose, measured without regard to any attenuation (noise reduction) from hearing protectors.

OSHA's noise standard calls this trigger the action level. Once any worker reaches it, you must have a hearing conservation program.

The exclusion of hearing protectors is the key to the whole standard. Handing out earplugs does not move you below the action level, and it cannot, because the action level is measured on the noise and not at the ear.

"Everyone wears plugs" does not take the place of the program. Hearing protectors are one of seven elements the standard requires once anyone reaches the action level.

The two trigger levels

The exchange rate is 5 decibels, meaning each added 5 decibels cuts the allowed time in half. That is OSHA's rate. Most of the rest of the world uses a 3 decibel exchange rate, which is why US and international noise studies of the same workplace come out with different numbers.

When hearing protection alone can satisfy the standard

Table G-16 is OSHA's table of permissible noise exposures. Where workers are exposed above its limits, the noise standard requires feasible engineering or administrative controls.

The standard then adds a second step. If those controls fail to bring sound levels within the limits, personal protective equipment must be provided and used to bring sound levels within the table.

So under OSHA, hearing protection can be your means of compliance where those controls are not feasible.

The seven program elements

Once anyone reaches an 8-hour TWA of 85 dBA, you owe all of the following:

When monitoring has to be repeated. The noise standard requires new monitoring whenever a change in production, process, equipment or controls increases noise exposure. The increase has to meet one of two conditions:

• More workers may be exposed at or above the action level, or
• The attenuation of the hearing protectors in use may no longer be adequate.

Both conditions turn on an increase. A change that leaves exposure where it was, or lowers it, does not by itself require a new survey, and the standard sets no annual schedule for one.

Note the record retention periods. Most chemical exposure records fall under a 30-year default that comes from OSHA's standard on access to exposure and medical records, and the noise periods are far shorter. The audiometric test record also outlasts the noise survey by decades, which becomes a problem when a claim arrives years later.

→ Access to exposure and medical records

Audiometric testing deadlines

This is where programs slip most often, because the clock starts on a hire date.

A baseline audiogram within 6 months of a worker's first exposure at or above the action level. The baseline is the reference against which later audiograms are compared.

Or within 12 months, where the employer uses a mobile test van to meet this requirement. That extra time comes with a condition: where the baseline is delayed beyond 6 months, the worker must wear hearing protectors for any period past 6 months after first exposure, until the baseline audiogram is done.

Annually after that, for every worker in the program.

The mobile van route is common and fully permitted. What gets missed is the hearing protector condition attached to it, which sits in the timing paragraph of the standard and not in the hearing protector paragraph.

→ Standard threshold shift (STS): when an audiogram shows a drop in hearing

What a complete program looks like on paper

• Current noise monitoring that identifies every worker at or above an 8-hour TWA of 85 dBA, using noise dosimeters worn by the workers where the standard calls for them
• Written records showing that each of those workers was notified of the results
• A baseline audiogram for each, dated inside the window that applies
• Annual audiograms with a written comparison against the baseline
• Evidence that workers were offered a choice of protectors, not issued a single type
• Annual training records showing content, date and attendance
• Records retained for the periods the standard sets

That makes seven items. Two gaps turn up most often: the records showing workers were notified of their results, and the written comparison against baseline. Both sit between the audiometric testing provider and the employer, and each side tends to assume the other holds them.

When you may not need this

If nobody in your plant reaches an 8-hour TWA of 85 dBA, none of the hearing conservation requirements in OSHA's noise standard apply. A written survey is what demonstrates it.

A floor that sounds loud on a walkthrough is not the test, because the sound level at one moment is not the dose over a shift. An 88 dBA area that a worker occupies all day produces a higher dose than a 100 dBA machine run for 45 minutes. The only way to know is to measure the right thing on the right people.

→ How many employees to sample for noise

What we do

Our part is the noise survey. Workers wear noise dosimeters set to count sound from 80 dBA up, and a sound survey groups workers by how much of the shift each one spends in the noise, not by machine.

The report should give each worker's 8-hour TWA and dose, and compare both against the action level and the PEL. A useful report also states which of the seven elements each result triggers, and by when.

We do not perform audiometric testing, train workers or manage the program. Those elements are outside the four fields we work in.

→ Noise surveys · → Personal noise dosimetry · → Hearing protector selection · → Octave band analysis