Inner Ear Can 'Store' Recent Sounds, Study Finds
Vibrations in the ear continue briefly after a sound has ended, researchers say
TUESDAY, April 5, 2011 (HealthDay News) -- 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."
The U.S. National Institute on Deafness and Other Communication Disorders outlines signs of hearing loss.