Otoacoustic emission suppression testing: A clinician's window onto the auditory efferent pathway

Abstract

There has been considerable progress in the last decade in understanding the role of the auditory efferent pathway. This is exemplified by the development of tests for the suppressive effect of contralateral noise on the production of otoacoustic emissions by the outer hair cells of the cochlea. Suppression of OAEs is demonstrably subserved by the auditory efferent pathway, as carried in the inferior vestibular nerve. Advances in the development of testing the suppressive effects of noise have been paralleled by application to a variety of relevant clinical scenarios, enhancing and refining the use of this test in routine clinical practice. In particular, OAE suppression testing has been proposed in the assessment of cerebello-pontine angle tumours, multiple sclerosis, myasthenia gravis, auditory neuropathy/dys-synchrony and auditory processing disorders. This review considers these advances, along with practical issues and pitfalls in testing. OAE suppression testing is the most widely accessible method of testing auditory efferent function in the clinic, but consensus has yet to be achieved as to a standard protocol, and interpretation of this test, and elements of the underlying physiology remain incompletely understood. It is a useful addition to the audiological test battery, allowing the clinician a window onto the auditory efferent pathway.

• otoacoustic emissions
• auditory efferent pathway
• contralateral suppression