Hearing Loss and Tinnitus due to Military Service is a growing problem. VA reported that the 2.5 million veterans receiving disability compensation had approximately 6.8 million separate disabilities related to their military service.
Among military veterans, the most common service-connected disabilities are hearing impairments, suggesting that occupational noise exposure during military service might cause more veterans to have hearing loss than nonveterans.
“Hearing loss affects more than 28 million Americans, including more than half of those over age 75.”
Hearing problems – including tinnitus, which is a ringing, buzzing, or another type of noise that originates in the head, are by far the most prevalent service-connected disability among American Veterans.
Disabilities of the Auditory System due to Military Service
For the roughly 158,000 veterans who began receiving compensation in 2003, auditory disabilities were the second most common type of disability.
“These veterans had approximately 75,300 disabilities of the auditory system out of a total of some 485,000 disabilities.”
The most common service-connected disabilities are hearing impairments, suggesting that occupational noise exposure during military service might cause more veterans to have hearing loss than nonveterans.
Veterans were 30% more likely to have SHI than nonveterans after adjusting for age and current occupation, and veterans who served in the United States or overseas during September 2001-March 2010.
The era of overseas contingency operations (including Operations Enduring Freedom and Iraqi Freedom), were four times more likely than nonveterans to have SHI.
Noise and Military Service
Many sources of potentially damaging noise have long existed in military settings. For the period since World War II to the present some of these sources include:
- Weapons systems
- Wheeled and tracked vehicles
- Fixed- and rotary-wing aircraft
- Communications devices
Service members may encounter these noise sources through training, standard military operations, and combat. Exposure to combat-related noise may be unpredictable in onset and duration.
Service members may also be exposed to hazardous noise through activities that are not unique to the military environment, including various:
The Measurement of Hearing and Tinnitus
In humans, hearing loss is typically measured by behaviorally determining the minimum sound pressure level that can be heard about 50 percent of the time, defined as the hearing “threshold”.
“At each of several frequencies using pure tones ranging from 250 to 8000 Hz in octave steps.”
Pure tones at frequencies of 1500, 3000, and 6000 Hz are also frequently included, especially when sharp declines in high-frequency hearing are observed or anticipated.
There is a range, generally accepted to be -10 to 25 dB HL at each frequency, that is considered to be representative of “normal” hearing in adults.
As hearing thresholds increase beyond the maximum level of the normal range (> 25 dB HL), the degree of hearing loss in adults can be described as:
The specific noise levels that cause noise-induced hearing loss vary with the duration of the exposure, the type of noise, and the frequency content of the noise, as well as the susceptibility of the exposed individual.
Time-weighted average noise exposures of approximately 85 dBA for 8 hours per day for a 40-hour workweek, or the equivalent, are considered to be hazardous, but a person must be so exposed for a number of years before developing noise-induced hearing loss.
Impulse noise with peak levels exceeding approximately 140 dB SPL may be hazardous even for a single exposure.
With regard to noise-induced tinnitus, specific parameters of hazardous noise exposure have not been defined, but noise levels associated with hearing loss are also likely to be associated with tinnitus.
What Causes Tinnitus in the Military
Tinnitus is the number-one disability among Veterans and affects at least 1 in 10 American adults. People with tinnitus describe ringing sounds, a buzzing sound, a high-pitched whistle, or numerous other sounds.
Chronic tinnitus is the persistent perception of sound that has no external source. An estimated 3–4 million U.S. military Veterans have tinnitus, of whom up to 1 million require clinical intervention.
It was recently reported that Veterans have twice the prevalence of tinnitus as non-Veterans.
It would seem likely that noise exposure in the military (weapons fire, aircraft, explosions, etc.) increases the prevalence of tinnitus in Veterans.
“Veterans can claim tinnitus as a service-connected disability. When approved, tinnitus claims nearly always result in a 10 percent disability rating, which qualifies the claimant for monthly compensation. “
The number of tinnitus disability claims has increased dramatically in the last 10 yr, and according to the Veterans Benefits Administration, tinnitus has been the most prevalent service-connected disability since 2008. (www.vba.va.gov/reports/abr/index.asp).
About 80 percent of people with tinnitus are not bothered by it, because it does not affect their sleep or their ability to concentrate.
Those who struggle with the noise in their head can be more prone to other mental health problems, such as depression and anxiety.
Testing for Tinnitus
Tinnitus is common in Veterans, but there are no objective tests to diagnose the problem.
In 2013, NCRAR researchers and researchers from Oregon Health and Science University conducted three phases of testing to try to distinguish Veterans with tinnitus from those who do not have it.
They found some differences between the groups, but also that no single test or series of tests could reliably diagnose the condition.
The team concluded additional work is needed to develop a specific battery of tests for detecting the presence or absence of tinnitus with a high degree of confidence.