Inner Ear Can 'Store' Recent Sounds, Study Finds
TUESDAY April 5, 2011 -- The inner ear can actually "store" sounds, according to a new study.
Scientists found that vibrations in the inner ear continue even after a sound has ended and may serve as a mechanical memory of recent sounds.
The study is published in the April 5 issue of the Biophysical Journal.
In research with guinea pigs, the investigators found that after-vibrations in the inner ear were dependent on the magnitude and frequency of the sound stimuli and that even minor hearing loss resulted in a major reduction in after-vibrations.
"The after-vibrations appear to be driven by sustained force production in the inner ear -- a form of short-term memory of past stimulations," study senior author Dr. Alfred L. Nuttall, of the Oregon Hearing Research Center, said in a journal news release.
"It is important to point out that although our findings clearly demonstrate the existence of after-vibrations, further work is needed to elucidate the underlying mechanism," he added.
Nuttall explained the potential importance of after-vibrations for hearing.
"The ability to detect brief gaps in an ongoing stimulus is critical for speech recognition; gaps need to be longer than a minimal interval to be perceived. To the extent that after-vibrations excite the auditory nerve fibers, they may explain part of the difficulty in detecting such gaps."
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Posted: April 2011