A Preceding Sound Expedites Medial Olivocochlear Reflex

The current study investigated the effect of a preceding sound on the medial olivocochlear reflex (MOCR), which is a sound-activated feedback response that controls the input to the auditory system. We used 60- and 40-dB noise and a 40-dB tone burst as preceding sounds, and evaluated their effects on the time course and strength of the MOCR. The MOCR was assessed non-invasively in terms of the suppression of otoacoustic emissions induced by contralateral acoustic stimulation. We found that (1) all the preceding sounds we used, regardless of whether they induced an MOCR by themselves, expedited the MOCR by up to 90 ms, and (2) a 60-dB-preceding-noise, which itself induces an MOCR, not only expedites but also enhances the MOCR.

© 2018 The Author(s). Published by S. Hirzel Verlag · EAA. This is an open access article under the terms of the Creative Commons Attribution (CC BY 4.0) license (https://creativecommons.org/licenses/by/4.0/).