Effects of contralateral white noise on click-evoked emissions in normal and sensorineural ears: towards an exploration of the medial olivocochlear system.

The association between contralateral stimulation and evoked otoacoustic emissions (EOAEs) allows study of sound-evoked olivocochlear feedback and then of the medial olivocochlear system. A method allowing quantification of sound-evoked olivocochlear feedback is proposed. The feedback is present in almost all normal-hearing subjects, but with great interindividual variability. In sensorineural hearing loss, the feedback is present in 20 out of 21 subjects. One paradoxical clinical case is described with a unilateral increase of EOAE intensity during contralateral stimulation.