In an article published in the latest edition of The Journal of Neuroscience, Larry Roberts, a professor in the Department of Psychology, Neuroscience & Behaviour at McMaster University, and his co-authors report evidence that the tinnitus sound—described by most tinnitus sufferers as a constant high-pitched ringing or hissing noise—is generated by neurons firing in the brain, not the ear.
“Hearing loss associated with noise exposure or the aging process sets the occasion for the large majority of cases of tinnitus,” he says. “Tinnitus itself is brought on by changes in the brain that take place when hearing loss occurs”.
While tinnitus is most common after the age of 60, where 8 to 20 per cent of adults are affected, chronic tinnitus can occur at any age and is a major cause of service –related disability in soldiers returning from Afghanistan or Iraq.
“Studies show hearing loss among young people is increasing and we may see an increase in cases of tinnitus as a consequence of mild hearing losses induced by recreational sound,” says Roberts. “The implications underscore the need for more public policy on prevention. Much like the movement that swayed public opinion on the dangers of cigarette smoking and the need for cessation, we need new initiatives on hearing loss.”
Roberts will be part of a symposium presenting ground breaking research on tinnitus at the Society for Neuroscience meetings in San Diego on November 14th.
Other symposium members are Jos Eggermont (University of Calgary), Donald Caspary (Southern Illinois University School of Medicine), Susan Shore (University of Michigan), Jennifer Melcher (Harvard Medical School), and James Kaltenbach (The Cleveland Clinic).
Their studies describe how hearing loss modifies the activity of neurons in auditory pathways and how other brain processes are affected, including those involving the muscle and skin senses, emotion, and inhibitory functions that change with aging and likely contribute to tinnitus.
McMaster University, one of four Canadian universities listed among the Top 100 universities in the world, is renowned for its innovation in both learning and discovery. It has a student population of 23,000, and more than 140,000 alumni in 128 countries.
For more information, please contact:
Public Relations Manager, Broadcast Media
905-525-9140, ext. 22869
Editors: a high res photo of Larry Roberts can be downloaded at http://dailynews.mcmaster.ca/images/larry.jpg