Topics at international conference of ENT researchers - Part One

Editor: Ever wonder what kinds of research ENT researchers are pursuing? If so, you'll be interested in some of the presentations at an international conference of ENT researchers. Many of these topics have been covered in the hearing loss media, but some are new, at least to me. I think they're all pretty interesting!

This is part one of two parts.

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February 2009

Our Aging Ears and Brains: Why Listening in Background Noise Gets Tougher as We Age

Older adults often have trouble understanding what someone is saying when surrounded by background noise, such as at a restaurant or party, but their ears may not be the only problem. Researchers at the Medical University of South Carolina are studying how much the brain plays a role as well. Using magnetic resonance imaging (MRI), the researchers performed brain scans on 36 older and younger adults as they tested their ability to identify certain words, some of which had been filtered to make them difficult to understand. The researchers analyzed the scans to functionally define speech- and attention-related areas of the brain and then examined the volume of gray matter in those regions for age-related changes. They found that, in general, older adults were significantly worse at identifying words than younger adults in challenging listening conditions. Even after eliminating variation due to possible hearing loss, these differences in performance corresponded closely to a loss of volume in a small portion of the auditory cortex, a part of the brain that processes what our ears hear. What's more, the relationship between the volume of gray matter in this brain region and the ability to identify words was present in both younger and older adults, suggesting that aging may intensify developmental problems that a person may have in understanding speech. The findings could help us better understand presbycusis, a type of hearing loss brought on by aging that also involves the brain's ability to process what the ears hear.

The poster "Structural Integrity of Speech-Related Temporal Lobe Cortex Predicts Age-Related Differences in Word Recognition" (#141) takes place Sunday, February 15, at 1:00 p.m. in the Grand Ballroom.

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Can a Dietary Supplement Stave Off Hearing Loss?

Many people take a vitamin each morning to maintain good nutrition, energy, bone strength, and overall health. Can popping a pill also protect our hearing against damage caused by loud noise? Researchers at the University of Michigan and the University of Florida, together with the biosciences company OtoMedicine, have demonstrated that temporary noise-induced hearing loss - the hearing loss you might feel immediately after attending a loud concert but that goes away in a day or two - can be prevented in guinea pigs by a combination of the antioxidants beta-carotene, vitamin C, and vitamin E and the mineral magnesium, when administered before exposure to a loud sound. Because repeated bouts of temporary noise-induced hearing loss may lead to permanent noise-induced hearing loss, the scientists hope to determine whether prevention of the former can stave off the latter in various animal models and in humans.

In a second study conducted with colleagues at Washington University, the researchers demonstrated that permanent noise-induced hearing loss can also be prevented in mice through the combination of the same nutrients administered before exposure to a loud noise. (They showed similar results in guinea pigs in an earlier study.) However, unlike in guinea pigs, they found that the nutrients protect a structure in the mouse's inner ear that is implicated in age-related hearing loss. They plan to test whether the nutrient supplements may be able to prevent this type of hearing loss as well. The researchers are currently conducting clinical trials of the supplements' ability to prevent noise-induced hearing loss in college students, military personnel, and factory workers in Florida, Sweden, and Spain.

The posters "Reduction in Permanent Noise-Induced Threshold Deficits in Mice Fed a Combination of Dietary Agents" (#826) and "Prevention of Temporary Noise-Induced Threshold Deficits Using Dietary Agents" (#827) take place Wednesday, February 18, at 1:00 p.m. in the Grand Ballroom.

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Finding the Words: What Our Brains Tell Us about Language Disorders

We rely mightily on our brains to produce and understand language - whether we're simply naming a person or object or engaging in a lively discussion. Technologies in brain imaging - from those involving the brain's electrical activity to those measuring blood flow to regions of the brain - can tell us a lot about what's happening in the process. Dr. Allen Braun, chief of the language section in NIDCD's Division of Intramural Research, will demonstrate how a combination of imaging technologies can be used to teach us more about how the brain produces and comprehends language, both in people with normal skills and those with a language disorder. In addition, he'll show how language used in its most natural form - to communicate - is most effective in bringing to light the true symptoms of a language disorder. In the same workshop, an opera singer who suffered a severe stroke in 1995 will describe her experience with expressive aphasia, a condition that makes it difficult to express language. She will also perform several music selections.

The presentation "Brain Networks for Language Production and Comprehension" (#227) takes place Sunday, February 15, at 7:05 p.m. in the Harborside Ballroom A-C. The presentation "A Case Study of Expressive Aphasia in an Opera Singer" (#228) immediately follows at 7:35 p.m. in the same location.

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Maintaining Balance and Listening at Same Time May Become More Difficult for Older Adults

Listening to a conversation or audio book while walking or exercising sounds simple enough for most people, but it may become more difficult for people in their upper 70s and above, according to new research from the University of Pittsburgh Medical Center. Researchers evaluated how well three groups of adults -- healthy young (ages 24-27), old (ages 65-71), and "old-old" (ages 76-82 years) -- were able to conduct a listening exercise while their visual and balance systems were kept busy. Seated in swivel chairs that were either upright or at a 30-degree tilt, the volunteers performed two listening-related tasks while motionless or spinning in darkness or in light. In one task, they listened to a high- or low-pitch tone and pressed a button in their right or left hand depending on the pitch. In the second task, volunteers listened to tones in their right or left ears and pressed the corresponding button. The researchers found that, in general, all age groups reacted more slowly to the audio cues when spinning than when motionless. However, this was especially true for people in the oldest age group. They also found that stimulation of the ear's gravity-sensing organs - through the 30-degree tilt of the chair -- was especially powerful in slowing down a person's auditory reaction time. Again, this effect was most pronounced for people in the oldest age group. The National Institute on Aging also supported this research.

The poster "Visual-Vestibular Stimulation Interferes with Auditory Information Processing Task Performance in Older Persons" (#961) takes place Wednesday, February 18, at 1:00 p.m. in the Grand Ballroom.