Otoacoustic Emissions (OAEs) 

Why?

This is an objective test to measure the outer hair cell function of the cochlea (the auditory part of the inner ear). Stimulation of the normal cochlea results in the transmission of an electrical impulse along the auditory nerve through the brain to the auditory cortex where it is perceived as sound. At the same time some sound (cochlear echo) is reflected from the cochlea to the external canal and can be measured by a sophisticated recorder.

How?

You are not required to do anything for this test other than sit very still. The audiologist will hold a soft rubber probe at the entrance of your ear canal and you will hear some clicking sounds but you are not required to respond to them.