Acoustic reflex

The acoustic reflex (or stapedius reflex) is an involuntary muscle contraction that occurs in the middle earof mammals in response to high-intensity sound stimuli.

When presented with a high-intensity sound stimulus, the stapediusand tensor tympanimuscles of the ossiclescontract. The stapedius pulls the stapes(stirrup) of the middle ear away from the oval window of the cochleaand the tensor tympani muscle pulls the malleus(hammer) away from ear drum. The reflex decreases the transmission of vibrational energy to the cochlea, where it is converted into electrical impulses to be processed by the brain. The acoustic reflex normally only occurs at relatively high intensities; activation for quieter sounds can indicate ear dysfunction and absence of acoustic reflex can indicate neural hearing loss.

See also

• Otoacoustic emission

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It uses material from the http://en.wikipedia.org/wiki/Acoustic+reflex Wikipedia article Acoustic reflex.