ABERDEEN PROVING GROUND, Md. – May’s Better Hearing and Speech Month is an opportunity for the U.S. Army Public Health Center to remind Soldiers to protect their hearing for both their long-term quality of life and to avoid potentially dangerous conditions in combat.
According to the Veterans Administration, two of the top three reasons for military disability compensation claims are hearing loss and tinnitus, a chronic ringing, buzzing or whistling in the ears. Active-duty service men and women also experience these conditions.
The primary cause of these conditions among military personnel is noise exposure. Noise-induced hearing loss and tinnitus can result from repeated unprotected exposures to loud noises over years of service, or a one-time unprotected exposure to an extremely loud noise, such as firearms or other weapon systems.
Noise from weapons are a recognized hazard at firing ranges and in infantry and artillery settings. Likewise, aircraft carriers, flight lines, helicopters, and naval ship engine rooms are considered to be some of the loudest environments in the military.
But exposure to loud noise can happen in a variety of other military settings.
“Noise doesn’t just happen in combat; loud noise conditions occur during training and industrial installation base operations,” says Col. Amy Blank, audiologist and chief of the APHC Hearing Conservation Readiness Branch. “Noise levels can also go from acceptable to too loud depending on changing external factors.”
Blank uses the example of various transport vehicles, like the Humvee. Certain conditions, such as speed, driving on a gravel road instead of a paved road, or with open windows or doors, can drastically increase the noise level. The cumulative effect of repeated exposures to these loud noises can result in hearing loss.
Department of Defense policies quantify excessively loud noise as a daily 8-hour average exposure of 85 decibels or more, or a single peak exposure of 140 decibels. These criteria are used to identify high-risk environments and determine the inclusion of civilian employees in DOD hearing conservation programs. Because of noise exposures and their associated risks to performance, the Army requires annual hearing testing for all Soldiers, not unlike their annual vision and dental check-ups.
“Because measuring decibels is often not practical, people can determine if they are in an environment that is too loud by using the three-foot rule, or arm-length rule,” says Blank. “If you have to raise your voice to be heard by someone an arm’s reach away, consider the background noise too loud and wear hearing protection.”
For any Soldier or civilian, reducing exposure to loud noises as much as possible can protect the ability to hear. Hearing loss can occur immediately after an extremely loud noise or blast but often occurs gradually. Some individuals eventually notice they have difficulty understanding parts of everyday conversation.
“But even a less noticeable loss of hearing can have immediate and dangerous impact to Soldiers,” says Blank. “Soldiers need to be able to hear clearly in environments with extremely loud background noises, like engine and vehicle noises and gunfire. Even slight decreases in hearing can affect the ability to understand speech and lead to mission degradation or mission failure.”
To protect personnel from developing hearing problems, the Occupational Safety and Health Administration and the DOD require hearing conservation programs for personnel at high risk for hearing loss. This program includes annual hearing health education, hearing protector fitting, and monitoring hearing tests known as audiograms.
DOD hearing experts like those at the APHC ensure personnel undergo annual audiometric monitoring for early identification of hearing loss. Historically, the DOD’s audiogram tests were only performed in booths designed to test to up to eight people at a time. Over the last two years, however, booth capacity was limited by social distancing requirements and cleaning protocols to prevent potential COVID exposures. APHC experts were able to meet the challenge by piloting a more flexible technology that uses a wireless handheld device.
“Our use of boothless audiogram technology has shown DOD and Army stakeholders that they can meet mission requirements with a medically ready force without reliance on testing inside the confines of a sound booth,” says Blank. “This technology can provide for more flexibility and convenience by bringing testing to the service members, in garrison and while deployed.”
While annual audiometric monitoring is a key element of maintaining a hearing-ready force by identifying early changes in hearing, APHC experts are advancing the science in other ways, too.
“We recognized that the same boothless audiometric technology can be used to actually tell us how much a Soldier’s hearing protection is reducing noise in that individual’s ears,” says Blank. “Hearing experts have always relied on product certifications for hearing protection and had to assume everyone had the right amount of protection, that is, if the hearing protector is
worn properly. The ability to test individuals’ protection level is an emerging technology called “hearing protector fit check.”
Blank explains that while she and other Army and DOD experts provide input to policies and equipment development to help reduce the noise exposure experienced by service members, much of it cannot be avoided. So, it is up to leaders and Soldiers to safeguard their hearing by wearing hearing protection.
Hearing protection devices include ear muffs, certain helmets and, most commonly, ear plugs, both the foam and preformed plastic types. Some hearing protection has a built-in noise reduction or communication capability. The type of device used should be based on the type of noise reduction needed, as well as communication needs.
Audiologists are often asked, “Which hearing protection is the best?”
“The best hearing protection is one that is worn correctly and when it should be,” Blank says. “Different types may fit or feel better in one Soldier than another, and even a single person may have different shaped or sized ears. So, comfort is a key factor in selecting the best type for an individual. Our ability to test how well specific devices used by a Soldier actually work will also be essential in this decision.”
While these scientific advances are improving our capabilities, Blank emphasizes the need for commanders and leaders to reemphasize the need for Soldiers to take their hearing seriously and wear hearing protection routinely.
Years ago, leaders often required Soldiers to maintain earplugs on their uniforms, such as in cases attached to a button hole for immediate access to their hearing protection, explains Blank.
“Since today’s uniform does not have button holes, earplugs—if carried—are worn elsewhere, like through a belt loop,” says Blank. “If they are out of sight or less available, they may be used less, which could increase risk of hearing loss.”
Finally, because hearing loss can result from the additive effects of many exposures, Soldiers should also use hearing protection during off-duty activities such as marksmanship and hunting and while using lawn mowers, power saws, or other noisy machinery. Blank says, “Remember the three-foot rule; it applies both on and off duty for you and your family members.”