Otoacoustic emissions testing is a valuable tool that allows us
to assess the hearing status for hard to test populations from
newborns to adults, identify changes to the inner ear before
behaviorally a difference is noted and can be used to test the
effects of ototoxic drugs. Otoacoustic emissions testing is a
fairly recent addition to our hearing test battery. The test is
a quantitative test requiring no response from the person being
tested. A series of paired tones are sent into the inner ear
through a small probe fit into the outer ear canal. In a healthy
ear, the inner ear will respond with a corresponding tone
(sometimes referred to as an echo or an emission) that is picked
up by a sensitive microphone in the probe tip. The presence of
an appropriate emission tells us that the inner ear (cochlea) is
responding.