The Department of Defense will soon require fit testing for hearing protection to guard against future hearing loss and maintain fitness for duty.

Without hearing protection, service members and DOD civilians are at risk of permanent hearing loss when exposed to high noise levels like firearms, explosives, vehicle noise, and “continuous hazardous noise whether the exposure occurs on- or off-duty,” according to Theresa Schulz, the Defense Health Agency Hearing Center of Excellence chief of the prevention and surveillance section and a doctor of audiology. The center is a branch of the DHA Research and Engineering Directorate.

On the positive side, an HCE report for FY 2021 on military hearing conservation found military hearing losses to be at stable levels.

“Although it is stable, it’s not improving,” said U.S. Army Lt. Col. Michael Murphy, the U.S. Army audiology liaison at HCE and chief of the studies and analysis section. Hearing loss and tinnitus remain the number one and number three disability claims for the Department of Veterans Affairs, respectively, he said.

What a Fit Test Measures

“Referrals for a hearing protector fit test are generated from the hearing conservation clinic at your local military hospital or clinic or other hearing professionals embedded in occupational health, industrial hygiene, or safety,” Murphy said.

Your personal attenuation level, or PAR, “is an objective measure of total hearing protection provided by your hearing protector. The PAR may fluctuate depending on the placement of the hearing protector, such as depth in your ear canal or other characteristics specific to your ear,” he said.

“Hearing protectors with a PAR that reduces the noise below 85 decibels of continuous sound pressure level and below 140 decibels of peak sound pressure can mitigate the risk from hazardous noise,” Murphy explained.

Importance of Fit Testing

There are potential issues with current hearing protective device standards that fit testing can address, said Dr. Doug Brungart, the senior hearing scientist at the National Military Audiology and Speech Pathology Center at Walter Reed National Military Medical Center in Bethesda, Maryland, who has a doctorate of electrical engineering.

According to Brungart, current standards for selecting and issuing hearing protection are designed to ensure roughly 95% of all individuals who use a device without fit-test verification are able to obtain enough noise reduction to prevent them from exceeding their maximum allowable daily noise exposure.

However, some users may have more protection than needed, which can make it difficult to maintain awareness of voices, alarms, and other important sounds in the environment. There may also be some extremely noisy environments where a substantial number of service members do not receive as much protection as they require, Brungart explained.

By comparison, “fit testing can tell us the true attenuation an individual is getting from a hearing protector, rather than forcing us to rely on selecting a protector with much more noise reduction than is needed to obtain a wide margin of safety to protect listeners who have a relatively poor fit with the device,” Brungart said.

Updated DOD Fit-Testing Policy Forthcoming

A revised DOD Instruction 6055.12 will update the August 2019 policy and address the Centers for Disease Control and Prevention’s position that “fit testing is an effective, practical, and essential tool for preventing occupational hearing loss.”

Under the revised instruction, all DOD personnel enrolled in their service’s hearing conservation program and exposed to high noise levels, at or above 95 decibels over an 8-hour average, will get a hearing protector fit test when they enroll in the hearing conservation program. Testing happens before initial duty in hazardous noise areas or as soon as possible after employment begins.

DOD personnel exposed to continuous and intermittent noise at or above 85 decibels as measured in this 8-hour average or impulse noise sound pressure levels of 140 decibels or greater for at least one day per year must be enrolled in a hearing conservation program.

The Defense Centers for Public Health-Aberdeen said hearing conservation and readiness programs “reduce the impact of hazardous and occupational noise-exposures to maintain fitness for duty and protect mission readiness and situational awareness in training, garrison, and deployed environments.” All U.S. Army soldiers are already enrolled in hearing conservation programs.

Additional criteria for hearing protection fit testing will go into effect with the new DOD instruction, currently expected for release by December 2023.

The instruction addresses the minimum requirements for hearing protector fit testing in the DOD, HCE said. Each service may have more stringent requirements for hearing protector fit testing that better meet the needs of their hearing conservation program, HCE explained.

‘Last Line of Defense’

Schulz shared advice about hearing protectors, which she called “the last line of defense from noise-induced hearing loss,” including:

• Find hearing protectors that work for you.
• Ensure you fit them appropriately.
• Use them whenever you are exposed to hazardous noise.
• Fit testing is a powerful training tool to ensure wearers know “what right feels like.”

“There are hearing protector solutions that simultaneously protect you from hazardous noise and safely allow you to identify warning signals and maintain communication,” Murphy noted.

“Sudden changes to your hearing noted from hazardous noise, such as firing your weapon, may be indicative of permanent hearing loss,” Murphy said. “See your hearing conservation clinic or hearing professional immediately for medical management if your symptoms do not resolve within 36 hours.”

Additional advice from the Walter Reed National Military Audiology and Speech Pathology Center includes:

• Make sure other personal protective equipment doesn’t interfere with the ability to properly fit hearing protection, such as protective eyewear, that can result in an air leak for earmuff protectors.
• Hearing protectors are not a one-size-fits-all solution. If there are issues with a particular model, try a different solution, so long as the noise reduction levels are appropriate for the environment.

“Good hearing is a key to mission success—increasing operational efficacy and survivability in combat, increasing mission and training effectiveness and, maintaining quality of life,” Schulz said. “What sounds are important to you? How would you feel if you could no longer hear them? How would that loss affect your quality of life and mental health?”