Liberman M. Charles
- Japan Otological Society
- Otology Japan (ISSN:09172025)
- vol.5, no.2, pp.105-111, 1995-05-15 (Released:2011-06-17)
Anti-masking effects mediated by the sound-evoked efferent activity were discussed in the present paper. In the cats, masked auditory responses were enhanced by adding the noise to the contralateral ear both in the compound action potential (CAP) and in the responses of single auditory nerve fibers. These anti-masking effects were disappeared when the olivocohlear bundle (OCB) was interrupted. It has been suggested that classic suppressive effects of OCB on the auditory-nerve responses to the back ground masker are an important component of this OC mediated anti-masking phenomenon. Similar anti-masking phenomena were observable in the human subjects as well. Small but significant enhancements of masked CAP in amplitude were seen in some patients with facial palsy, in which acoustic reflexes of middle ear muscles (MEMs) had disappeared or were impaired.