A Tribute to Our Nation’s Veterans

By Laura Friedman

Each year on Veterans Day, November 11, we proudly honor the men and women who have bravely served our country and fought to protect our freedoms.

Veterans Day is important because it honors our soldiers and it is a time to raise awareness about their experiences on and off the battlefield. Noise-induced hearing loss (NIHL) and tinnitus (ringing in the ears) are the top two health conditions among military veterans, according to the U.S. Department of Veterans Affairs (VA). By the end of fiscal year 2016 over 1 million veterans received disability compensation as a result of hearing loss, and about 1.6 million received compensation for tinnitus.

In addition to being disproportionately affected by hearing loss and tinnitus, our soldiers and veterans are also more susceptible to developing central auditory processing disorders (CAPD). CAPD occurs when one can hear sounds but is unable to understand the words. It is sometimes caused by intense exposure to sudden and loud noises from improvised explosive devices (IEDs), ammunition and engine noise.

"Both post-blast trauma and CAPD are difficult, diffuse disorders where more work is needed, particularly on people working in extreme conditions, acoustic and otherwise, such as veterans." —Edward Bartlett, Ph.D., Associate Professor, Biological Sciences and Biomedical Engineering Purdue University

Blasts can result in temporary hearing loss and put military personnel at risk. However, the word “temporary” should be approached with caution: Repeated short-term hearing loss can damage the sensitive hair cells in the inner ear, leading to permanent hearing loss.

Hearing loss and tinnitus as a result of noise is largely preventable. There’s a misconception that not using hearing protection would inhibit vital communication and mission readiness. With today’s increasingly sophisticated technology, soldiers no longer need to choose between protecting their ears or their lives. Wearing hearing protection such as noise-attenuating helmets, which use ear cups to protect against hazardous sound, or Tactical Communication and Protective Systems, which protect against loud noises while amplifying soft ones, can go a long way to reduce overall exposure, while ensuring vital communications.

Any form of hearing loss can be detrimental to soldiers on duty, as the ability to hear signs of danger and to communicate with fellow soldiers is crucial for mission success and survival. Off-duty, hearing loss and tinnitus can also impact one’s well-being.

Regardless of age, type of hearing loss, or cause, if left untreated or undetected hearing loss can lead to considerable, negative social, psychological, cognitive, and health effects. As a result, it can seriously impact professional and personal life, potentially leading to isolation and depression. Treating hearing loss can also decrease one’s risk of acquiring other serious medical conditions, such as cardiovascular disease, dementia, and diabetes.

Veterans who have acquired hearing loss and tinnitus, either as a result of war or through other causes, can seek treatment at their local Department of Veterans Affairs (VA) medical center. Through partnerships with local community providers, the VA offers comprehensive hearing health services including screening, evaluation, treatment, and/or management of hearing, tinnitus, and balance disorders.

While it may be daunting to take the initial step of having a hearing test, it is important to know there are many different treatment options available. Some forms of hearing loss, such as those that affect the middle ear, are treatable through surgery. Damage to the inner ear and auditory nerve can cause permanent hearing loss; however technologies such as hearing aids, assistive/alerting devices, TV and telephone amplifiers, and cochlear and other auditory implants can optimize residual hearing by amplifying sounds.

As for tinnitus treatments, many patients have seen improvements with counseling and sound therapy, cognitive behavioral therapy (CBT), and the use of white-noise machines. Be sure to discuss the cause of your hearing loss and tinnitus and various treatment options with your audiologist or ear, nose, and throat specialist (ENT).

“On this and every Veterans Day, HHF sincerely thanks our military and our veterans for their brave service and sacrifice. I would also encourage all members, past and present, to have their hearing tested and monitored by a hearing health professional on a regular basis.” —Nadine Dehgan, CEO, Hearing Health Foundation.

Please visit va.gov/directory/guide to find your local VA medical facility. Please also see our Fall 2017 issue of Hearing Health magazine, whose theme is Veterans & Seniors, available at hhf.org/magazine.

Cortical Alpha Oscillations Predict Speech Intelligibility

By Andrew Dimitrijevic, Ph.D.

Hearing Health Foundation Emerging Research Grants recipient Andrew Dimitrijevic, Ph.D., and colleagues recently published “Cortical Alpha Oscillations Predict Speech Intelligibility” in the journal Frontiers in Human Neuroscience.

The scientists measured brain activity that originates from the cortex, known as alpha rhythms. Previous research has linked these rhythms to sensory processes involving working memory and attention, two crucial tasks for listening to speech in noise. However, no previous research has studied alpha rhythms directly during a clinical speech in noise perception task. The purpose of this study was to measure alpha rhythms during attentive listening in a commonly used speech-in-noise task, known as digits-in-nose (DiN), to better understand the neural processes associated with speech hearing in noise.

Fourteen typical-hearing young adult subjects performed the DiN test while wearing electrode caps to measure alpha rhythms. All subjects completed the task in active and passive listening conditions. The active condition mimicked attentive listening and asked the subject to repeat the digits heard in varying levels of background noise. In the passive condition, the subjects were instructed to ignore the digits and watch a movie of their choice, with captions and no audio.

Two key findings emerged from this study in regards to the influence of attention, individual variability, and predictability of correct recall.

First, the authors concluded that the active condition produced alpha rhythms, while passive listening yielded no such activity. Selective auditory attention can therefore be indexed through this measurement. This result also illustrates that these alpha rhythms arise from neural processes associated with selective attention, rather than from the physical characteristics of sound. To the authors’ knowledge, these differences between passive and active conditions have not previously been reported.

Secondly, all participants showed similar brain activation that predicted when one was going to make a mistake on the DiN task. Specifically, a greater magnitude in one particular aspect of alpha rhythms was found to correlate with comprehension; a larger magnitude on correct trials was observed relative to incorrect trials. This finding was consistent throughout the study and has great potential for clinical use.

Dimitrijevic and his colleagues’ novel findings propel the field’s understanding of the neural activity related to speech-in-noise tasks. It informs the assessment of clinical populations with speech in noise deficits, such as those with auditory neuropathy spectrum disorder or central auditory processing disorder (CAPD).

Future research will attempt to use this alpha rhythms paradigm in typically developing children and those with CAPD. Ultimately, the scientists hope to develop a clinical tool to better assess listening in a more real-world situation, such as in the presence of background noise, to augment traditional audiological testing.

Andrew Dimitrijevic, Ph.D., is a 2015 Emerging Research Grantee and General Grand Chapter Royal Arch Masons International award recipient. Hearing Health Foundation would like to thank the Royal Arch Masons for their generous contributions to Emerging Research Grants scientists working in the area of central auditory processing disorders (CAPD). We appreciate their ongoing commitment to funding CAPD research.

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Understanding Auditory Processing Disorder

 By Frankie Huang

April 4 is Auditory Processing Disorder Awareness Day and the Hearing Health Foundation is highlighting the effects and challenges associated with living with APD.

Auditory processing disorder (APD), also known as central auditory processing disorder (CAPD), is an auditory deficit affecting how the central nervous system interprets verbal information. Those living with APD show impairments in sound localization, specifically their ability to isolate a sound source in social environments.

Approximately 5% of school-age children have APD. Children with APD often are uncertain about what they hear and have difficulty listening in loud background noises as well as understanding rapid speech. Often distracted, they can struggle to keep up with conversations which impedes their ability to read, spell, and follow oral directions.

Researchers found a correlation between working memory capacity, which is the ability to retain and manipulate information, and speech development. They found that working memory capacity was significantly lower in children with APD and may be the cause of their inability to separate and group incoming information and, in turn, lead to poor speech perception in noisy environments.

Other researchers found that peripheral hearing loss may affect performance in certain APD tests in older adults. Older adults with mild to moderate hearing loss did significantly poorer on tests that require recalling words, identifying high and low tone patterns, and repeating short sentences.

Although APD can be difficult to diagnose, there are telltale signs: poor auditory memory, difficulty identifying sounds, and a delayed response to verbal requests and instructions. APD is sometimes misdiagnosed as ADD/ADHD or dyslexia, so if you suspect you or a loved one may have APD, it is advised that they go through an individual comprehensive assessment with an audiologist for a more accurate diagnosis.

It is important to understand that research is still needed to understand auditory processing disorders, accurate methodologies for diagnosis, and the best interventions for each child or adult. Even though there are available strategies to treat children with APD, researchers are hard at work finding alternative treatments that will improve the lives of those suffering from APD.

Learn about Hearing Health Foundation’s 2016 Emerging Research Grants recipients who are conducting research to improve the lives of those affected by APD. These grantees are General Grand Chapter Royal Arch Masons International award recipients and we are grateful to the Masons for their ongoing support.

Introducing HHF's 2016 Emerging Research Grant Recipients

By Morgan Leppla

We are excited to announce the 2016 Emerging Research Grant recipients. This year, HHF funded five research areas:

• Central Auditory Processing Disorder (CAPD): research investigating a range of disorders within the ear and brain that affect the processing of auditory information. HHF thanks the General Grand Chapter Royal Arch Masons International for enabling us to fund four grants in the area of CAPD. 
   
• Hyperacusis: research that explores the mechanisms, causes, and diagnosis of loudness intolerance. One grant was generously funded by Hyperacusis Research.
   
• Méniere’s Disease: research that investigates the inner ear and balance disorder. One grant was funded by the Estate of Howard F. Schum.
   
• Stria: research that furthers our understanding of the stria vascularis, strial atrophy, and/or development of the stria. One grant was funded by an anonymous family foundation interested in this research.
   
• Tinnitus: research to understand the perception of sound in the ear in the absence of an acoustic stimulus. Two grants were awarded, thanks to the generosity the Les Paul Foundation and the the Barbara Epstein Foundation.

To learn more about our 2016 ERG grantees and their research goals, please visit hhf.org/2016_researchers

HHF is also currently planning for our 2017 ERG grant cycle. If you're interested in naming a research grant in any discipline within the hearing and balance space, please contact development@hhf.org.