Hearing Conservation and Readiness

According to the Veterans Administration, two of the top three reasons for military disability compensation claims are hearing loss and tinnitus, External Link a chronic ringing, buzzing or whistling in the ears. Active-duty service men and women as well as civilian workers may also experience these conditions.

The primary cause of these conditions among military personnel is noise exposure External Link – this includes repeated unprotected exposures to loud noises over years of service, or even a single one-time unprotected exposure to an extremely loud noise.

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DOD's Hearing Center of Excellence
Defense Occupational and Environmental Health Readiness System – Hearing Conservation (DOEHRS-HC) DOD’s designated system for monitoring audiometry to detect changes in an individual’s hearing sensitivity.
NEW Journal article: Incidence of Self-Reported Bothersome Tinnitus Versus Tinnitus Diagnosis Among U.S. Army Soldiers (Oct 2024)
Significant updates to Hearing Policy: the Department of Defense Instruction (DoDI) 6055.12 “Hearing Conservation Program" 2024 update requires initial hearing protector fit-testing for all personnel with documented noise exposure > 95 dBA 8-hour time-weighted average and in a hearing program.
Defects found in certain 3M CAEv4 earplugs (CAC log-in required)
News articles:

Frequently Asked Questions

What is noise?

Sound that is annoying, makes communication or other tasks difficult, or is hazardous is called noise. External Link Sound (noise) is measured in decibels (dB). There are two primary types of noise:

Steady-state or repeated/continuous noise over a period of time is measured as a time-weighted average decibel level (dBA)
Impulse noise, is a single intense noise lasting for less than a second (e.g., a rifle shot or explosion) and is measured as a peak decibel level, or dB(P)

Some types of noises may be combinations of these two primary types – such as intermittent noise from helicopters overhead or jackhammers.

At what level is noise hazardous to workers?

Noise becomes hazardous when it can damage hearing – exposure to loud noise kills the nerve endings in our inner ear and can cause hearing loss. External Link

While an individual person's susceptibility can vary, damage from noise depends on how loud, how long, and how frequent a person's exposure.

While each occupational exposure setting should be evaluated by a professional to determine the degree of and type of hazard to personnel, health standards used are different for steady-state continuous noises versus impulse noises:

Sounds at or below 70 A-weighted decibels (dBA) are generally safe. As an example, a normal conversation with a person is estimated to be around 60-70 dBA.
Long or repeated exposure to sounds at or above 85 dBA may cause damage or hearing loss. For sounds that are above 85 dBA you likely have to raise your voice or shout to be heard by someone 3 feet away. Examples include certain motors like bulldozers, tanks, and chainsaws, but also nightclubs, concerts and large sporting events. This level of noise can damage hearing if repeated over time. The Occupational Health and Safety Administration (OSHA) requires employers (including DOD) to implement a hearing conservation program when workplace noise exposure is measured at or above 85 db average over an 8-hour time-weighted average (TWA).
OSHA also indicates that exposure to impulse noise should not exceed 140 dBP. These incidents can cause trauma to the inner ear and hearing tissues. At these levels, hearing protection must be worn in workplaces to prevent hearing loss.

What noise hazards are associated with military equipment and settings?

The military work environment is especially known for noise-related hazards External Link that exceed normal or safe levels. Examples (per sources ^1-2 listed below):

Several classes of military weapon systems expose Service members to impulse noise levels that exceed 180 dBP (e.g., mortar and howitzer systems, certain shoulder fired weapons systems)
Most military ground and air transportation platforms expose crew and passengers to steady-state (repeated/ continuous) noise higher than 85 dBA while operating, which means hearing protection must be worn so Hearing Conservation Programs are needed to monitor personnel hearing. Several military shipboard, ground, and air transportation and weapon platforms even create interior 110 dBA environments during operation.

Sources:

^1.Jokel, C., et al. Noise of military weapons, ground vehicles, planes and ships. J Acoust Soc Am 146 (5), 3832–3838, Nov 2019. https://doi.org/10.1121/1.5134069

^2.APHC Technical Information Paper (TIP) No. 51-003-0112, Noise Levels of Common Army Equipment. Jan 2012.

What does the military do to reduce health impacts of noise hazards to its personnel?

Hearing Conservation and Readiness Programs (HCRP) are required at each military installation to ensure that the military (including civilian) workforce is protected from hazardous occupational noise exposures. By reducing the impact of occupational noise hazards, an installation's HCRP promotes healthy hearing and quality of life and reduces the costs associated with work- and military-related hearing loss.

Examples of HCRP members and responsibilities include:

Industrial hygienists assess noise environments and activities and identify hazardous levels and applicable controls.
Audiologists and health technicians –

Monitor individuals' hearing (hearing tests used are primarily audiometry tests or audiograms)
Help determine individual hearing protection needs
Conduct medical fitness-for-duty assessments of service members to ensure combat mission readiness

Ensures members of the military and civilian workforce who are exposed to hazardous occupational noise are also surveilled and protected to reduce the impacts of noise-related hearing loss and tinnitus.
Ensures results of noise testing are documented in the DOEHRS-HC Data Repository.

How does a person know if hearing protection is worn correctly?

As a self-check to test hearing protection (“ear pro"):

When you tug on the ear protection, do you feel a vacuum seal?
Does your own voice sound louder when the ear protection is in?

If 'Yes' to both questions, the ear pro is seated properly.

More information can be found at:

Technical Products and References

Presentation: Leveraging boothless audiometers to implement hearing protection device fit-testing at Military Hearing Conservation clinics (Aug 2023)
Interim Impulse Noise Damage Risk Criterion (APHC 2020, 2015)

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Frequently Asked Questions

​Technical Products and References​

Technical Products and References