Office of Research & Development
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 other type of noise that originates in the head—are by far the most prevalent service-connected disability among American Veterans.
Some hearing loss can be reversed through surgery or medication. In other cases, hearing loss is permanent, but can be reduced through the use of hearing aids. Though almost all people with hearing loss could be helped by hearing aids, only about 1 in 5 who would benefit from them uses them, according to the National Institute on Deafness and Other Communication Disorders.
Conductive hearing loss, which is due to damage to the eardrum and middle ear structures, can often be reversed through surgery or medication. Sensorineural hearing loss, caused by damage to the inner ear and auditory nerve, is permanent, but can often be helped through the use of hearing aids.
As of the close of fiscal year 2014, more than 933,000 Veterans were receiving disability compensation for hearing loss, and nearly 1.3 million received compensation for tinnitus. In addition, many Veterans score normally on hearing tests but have difficulty understanding speech. This condition, called auditory processing disorder, is often associated with blast exposure.
VA researchers, engineers, and clinicians are studying ways to prevent, diagnose, and treat hearing loss. They are also addressing a wide range of technological, medical, rehabilitative, and social issues associated with tinnitus and blast exposure.
In 1997, VA established NCRAR to study hearing problems in Veterans, and to develop effective treatments. Researchers here work to alleviate communication, social, and economic problems resulting from hearing loss and tinnitus.
Among the topics studied at the center are methods of early detection of hearing loss; the effects of certain diseases or conditions, such as diabetes and multiple sclerosis, on auditory functioning; and the impact of auditory problems on speech perception.
Center researchers and their colleagues throughout VA system also looking at ways to improve speech recognition in noisy areas for people with hearing impairments, and studying the combined effects of aging and noise exposure on hearing.
In 2014, a team of researchers from the VA Loma Linda (Calif.) Healthcare System published a study that linked exposure to jet propulsion fuel-8 (JP-8) with auditory processing dysfunctions—changes that occur inside the brain rather than the ear.
In auditory processing dysfunction, people hear sounds properly, but the brain has a hard time deciphering the message. The research team believes that hydrocarbon chemicals in JP-8 may be the reason this occurs, and advocates for increased monitoring of the combined exposure of fuel and noise around aircraft.
Hearing aids are small electronic devices worn in or behind the ear that amplify sounds to someone with hearing loss. Although hearing devices have been used for centuries, the first electronic hearing aid was developed in the early 1950s. These devices have become smaller and more sophisticated over time.
It is VA policy that all Veterans enrolled in VA health care are eligible for medical services that include diagnostic audiology. Many Veterans are also eligible to receive hearing aids from VA.
Developing more advanced hearing aids—In 1992, VA and NIH began an innovative collaboration to support the development of more advanced hearing aids. Among the research projects funded were studies looking at how hearing aids affect speech understanding in noisy and quiet environments, and how to measure and predict the benefits of hearing aids.
In addition, the two agencies awarded a contract to support the design and evaluation of creative new technologies and strategies for hearing aids.
In 1995, VA, NIH, and NASA joined forces to survey all federal laboratories for acoustic or electronic technology that might help improve hearing aids.
In 1996, NIH and VA initiated the Hearing Aid Clinical Trial, the first large-scale clinical trial to demonstrate the effectiveness of three types of hearing aids in both quiet and noisy environments for a wide range of individuals with hearing loss. The study showed that all three types provide substantial improvement for people both in quiet and noise.
Group vs. individual visits for hearing aid services—In 2013, researchers at the VA Puget Sound Health Care System published the results of a study in which 644 people were asked to attend either group or individual visits for hearing aid fittings and follow up. The team found no differences in how well the hearing aids performed, or how often they were worn.
Group visits cost about half of what individual visits cost. Those who had group visits were more likely to wish they had more one-on-one time with an audiologist, but also reported they gained support and insight from other patients during the visits. The researchers concluded that group visits could reduce costs while providing community support for patients with hearing loss.
The research team also suggested that, in a group session, audiologists should take care to provide sufficient direct one-on-one interaction with each participant during a group visit, and all participants should be given time for hands-on practice with their hearing aids and opportunities to ask questions.
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.
The causes and effects of tinnitus vary from person to person. Because tinnitus has many causes, VA believes the approach to treating it should be interdisciplinary. And because there is no cure for tinnitus, VA's goal is not to silence the sounds it causes, but to help patients manage their reactions.
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.
Progressive Tinnitus Management—In 2006, an NCRAR research team developed the Progressive Tinnitus Management (PTM) approach. PTM is the culmination of years of studies and clinical trials, and is designed to address the needs of all patients who complain about tinnitus, while effectively utilizing VA's clinical resources.
Throughout the PTM process, Veterans work with a team of clinicians to create a personalized action plan to help manage their reactions to tinnitus and make it less of a problem. The five levels of management in the program include triage, evaluation, group education, interdisciplinary evaluation, and individualized support.
In 2016, VA announced that Dr. James Henry, the audiology researcher credited with leading the development of the PTM approach, was the recipient of the department's Paul B. Magnuson Award for the year. The Magnuson Award is the highest honor given to investigators by VA's Rehabilitation Research Service.
Tinnitus and mental health conditions—Also in 2016, a researcher at the Mountain Home (Tenn.) VA Medical Center and another with East Tennessee State University studied 199 Veterans with tinnitus. Some of the Veterans in the study had tinnitus only, some had tinnitus and a mental health condition other than posttraumatic stress disorder (PTSD), and others had tinnitus and PTSD.
The two researchers found that the group with tinnitus and PTSD were less confident in their abilities to successfully manage their tinnitus than either of the other two groups. They also found that the group with tinnitus and PTSD was most affected by the symptoms of their tinnitus, followed by the group with tinnitus and another mental health condition. The group with tinnitus only was least affected by their condition.
A similar study, conducted in 2015 by researchers at the VA Loma Linda Healthcare System and the Loma Linda University Medical School, found that 71.9 percent of the 91 Veterans with tinnitus they studied also had a diagnosis of anxiety, 59.3 percent had depression, and 58.2 percent had both conditions.
Patients with either or both conditions suffered from more severe tinnitus symptoms than patients without either condition.
Transcranial magnetic stimulation—Because tinnitus appears to involve over-active neurons in a part of the brain called the auditory cortex, VA researchers at NCRAR and elsewhere are studying the effects of a treatment called transcranial magnetic stimulation (TMS) on the condition. (Neurons are cells that transmit nerve impulses.)
In TMS, clinicians hold a magnetic coil, usually in the form of a figure eight, against the skull. The coil emits repetitive electromagnetic pulses that reach the brain cells under the scalp and change their activity pattern. This may help reduce the abnormal perception of sounds.
In a 2015 study, 32 Veterans received TMS treatments for 10 working days; another 32 received a placebo treatment. According to the study team, 56 percent of those who received the TMS treatment saw their tinnitus symptoms improve, compared to 22 percent of those who received the placebo treatment.
The team now hopes to conduct larger studies to develop protocols for ways this treatment should be best used.
Many Veterans who have served in Iraq and Afghanistan have been exposed to blasts during their service. VA researchers are learning about the varied effects of exposures to blasts on the brain.
Among these effects are hearing loss, which can occur in Veterans even when there is no obvious injury. A blast can compromise not only the ear itself, but also the connection between the ear and the brain.
Traumatic brain injury and sensory problems—Sensory problems are common among Veterans who have had traumatic brain injury (TBI). In 2012, VA researchers reported on a previous study of 21,000 Veterans evaluated for TBI in VA outpatient clinics. They found that 9.9 percent of them reported vision problems, 31.3 percent reported hearing impairments, and 34.6 percent reported both vision and hearing issues.
Frequency modulation—A study by NCRAR and Tampa VA researchers, completed in 2014, showed that frequency modulation (FM) may help Veterans who have normal hearing but problems understanding speech due to mild TBI.
The researchers tested an FM system, which uses radio waves to transmit signals directly from a microphone to an earpiece to make a speaker's voice more clear.
They also tested a "brain training" computer program that has users follow instructions or interpret sound. Preliminary results showed improved outcomes among those using the system.
Auditory processing—A 2015 NCRAR study looked at 99 Veterans who were exposed to blasts in Iraq or Afghanistan. All 99 had clinically normal hearing, but all reported problems hearing in difficult listening situations.
The research team asked study participants to participate in 10 performance-based tests that have been shown to uncover problems people may have in processing hearing signals. They found that many of the participants had difficulty in one or more of the tests compared to non-blast exposed Veterans, but that they also performed well in other tests.
The team therefore concluded that there was no common set of symptoms relating to problems with auditory processing experienced by Veterans exposed to blasts, but that blast injuries can and do result in damage to the central auditory system.
Chemotherapy drugs are potent weapons against cancer cells, but can have serious and permanent side effects, including hearing loss.
NCRAR researchers have developed a device, called the ototoxicity identification device (OtoID), which allows patients to easily and reliably test their own hearing. If the patients detect any hearing loss, doctors will be able to adjust the dose of the drug the patients are taking, or perhaps use a different one.
The system runs on tablet computers like iPads, and allows hearing test results to be transmitted back to VA clinics via a secure wireless network. Audiology staff then enter those results into patients' electronic health records, so that they can be shared with oncologists and other members of the patients' care teams.
Cisplatin is the most common chemotherapy drug linked to permanent hearing loss.
In 2015, the research team published the results of a study involving 21 Veterans undergoing cisplatin chemotherapy.
The team found that the OtoID had sufficient sensitivity to measure changes of hearing in these Veterans when they used the device at remote locations and the results of the testing was sent to an audiologist for evaluation.
Neuroscience may offer hope to millions robbed of silence by tinnitus, PBS Newshour, Nov. 6, 2013
WTAMU professor gains global attention for tinnitus research, NewsChannel 10 (Amarillo, Tex.), March 13, 2015
Study shows relief from tinnitus, debilitating ringing in ears, The Oregonian, July 16, 2015
Music to tinnitus sufferers' ears, The Dallas Morning News, Aug. 1, 2015
National program makes phone conversations easier for area Veterans with hearing loss, Waseca County News, Nov. 16, 2015
Prescribing hearing aids and eyeglasses, Veterans Health Administration Directive 2008-070, Oct. 28, 2008
Hearing Impairment Veterans Health Initiative, Office of Public Health, Department of Veterans Affairs
Quality of care: hearing loss, Department of Veterans Affairs
Hearing center of excellence, U.S. Department of Defense
Hearing loss, U.S. Library of Medicine, Medline Plus
Hearing loss, NIH Senior Health
Hearing Aids, National Institutes of Health Research Timelines
Hearing loss and deafness, womenshealth.gov.
National Institute on Deafness and Other Communication Disorders, National Institutes of Health
Buying a hearing aid, Federal Trade Commission consumer information
Hearing conservation, Occupational Safety and Health Administration, United States Department of Labor