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| Mark Eckert, Ph.D., right, prepares for an imaging experiment in the MUSC Center for Imaging Research, with colleagues Kenneth Vaden, Ph.D., and Stefanie Kuchinsky, Ph.D. Photo courtesy of Mark Eckert |
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| Mark Eckert, Ph.D. Photo courtesy of Mark Eckert, Ph.D. |
Not all hearing impairments arise from problems in the ear itself. Some can stem from issues in the brain. Gaining a deeper understanding of brain-based hearing loss is the aim of Mark Eckert, Ph.D., associate professor in the Department of Otolaryngology Head and Neck Surgery (Hearing Research
Program) at the Medical University of South Carolina (MUSC) in Charleston.
"A lot of hearing difficulties experienced by older adults, especially with respect to hearing speech, stem from hearing problems within the ear," says Eckert. "But once you account for those, there are still some unexplained factors that we think could be due to changes in brain function. This would involve changes in the central auditory pathway or attention-related systems in the brain."
Eckert and his colleagues believe this is the case because older adults with hearing loss seem to have more difficulty listening to and understanding speech in noisy environments when compared to younger adults with hearing loss. This observation suggests that older adults must have problems either filtering out irrelevant sound, or focusing on relevant sound.
The project Eckert is currently undertaking, with funding from the Deafness Research Foundation Centurion Clinical Research Award, will contribute to greater understanding of a treatment regimen developed by Larry E. Humes, Ph.D., professor in the Department of Speech and Hearing Sciences at Indiana University. Humes' treatment involves having participants listen to speech that has been amplified to sound like what a person wearing hearing aids would hear, with background noise. On a computer screen, the participant looks for words or sentences they just heard via amplification. Over a 12-week training session, with much repetition, people get better at identifying speech that is presented as it would sound through a hearing aid.
Of course, when speech is amplified via a hearing aid, the background noise gets amplified also, because it is difficult to make a hearing aid that amplifies only the speech you want to hear. Additionally, when someone gets a hearing aid, at first, words sound strange and quite different from how they used to sound, making it diffi cult for a new hearing aid-user to understand them. "What Larry Humes figured out was that you could effectively increase the signal-to-noise ratio through training," says Eckert. "So he uses a person's neural representation of visual words or orthography to help the brain re-learn the sounds of speech as heard via a hearing aid."
Eckert's job is to find out why Humes' program is working and to discover what aspects of the training are most effective. He employs functional magnetic resonance imaging (fMRI) to detect increased blood flow to certain parts of the brain, which occurs when neurons become more active and require more energy as the result of outside stimulation. Eckert evaluates brain response in participants both before and after they've undergone Humes' training regimen. Sometimes participants hear words and sometimes they see them. With fMRI, Eckert can identify which regions of the brain are excited by these different methods. By understanding the brain systems that are important in the success of Humes' program, the training can be optimized and may eventually be offered for home use, rather than requiring participants to go into a lab for 12 weeks.
Born in Ghana as the child of Peace Corps volunteers, Eckert studied psychology at Villanova University near Philadelphia, then earned a master's in experimental neuropsychology from George Mason University near Washington, D.C. He received a Ph.D. in psychobiology from the University of Florida, where he met his wife, Anita Ramsetty, an endocrinologist.
Though his research and family keep him busy, he does find time now and then to surf. "I like to fall off my surfboard," he jokes. "I'm not very good."
While Eckert's current focus is on hearing issues affecting older adults, his previous research was on childhood developmental disorders. "I still do developmental work," he says, "but the aging work has really become very exciting and fascinating to me, so it's taken over much of what I do. And my developmental background informs how I think about aging."
Part of his childhood development work involved studying twins. In an example of life imitating research, he and Anita have twin four-year-old girls of their own. "My wife won't let me scan them," he says, "but it's great to see them develop!"
For more information on the Deafness Research Foundation Centurion Clinical Research Award or The Centurions, visit www.drf.org/Centurions.
