The<unk>  (or stapedius<unk>  is an involuntary muscle contraction that occurs in the middle ear of mammals in response to high-intensity sound stimuli.
When presented with a high-intensity sound stimulus, the stapedius and tensor tympani muscles of the ossicles contract.  The stapedius pulls the stapes (stirrup) of the middle ear away from the oval window of the cochlea and the tensor tympani muscle pulls the malleus (hammer) away from ear drum.  The<unk>  decreases the transmission of vibrational energy to the cochlea, where it is converted into electrical impulses to be processed by the brain.  The<unk>  normally occurs only at relatively high intensities; activation for quieter sounds can indicate ear dysfunction and absence of<unk>  can indicate neural hearing loss.
Acoustic reflex
Optokinetic reflex
Trigonometric functions
Vocal resonation
Moro reflex
Pressure of speech
Vagovagal reflex
Cough reflex