It is neuro-electrical activity of hearing (auditory) system emerging as a response to specific types (click, logon, tone burst) of auditory stimulants. Its being a non-invasive measurement technique and being easy-to-apply and cheap are factors increasing its value. It has many indications. Its basic indications are: (a) Patients with cooperation difficulties (such as infants, children and mentally retarded people); (b) For collecting information about objective hearing thresholds; (c) As a differential diagnosis tool in existence or elimination or localization of lesions; (d) In inorganic hearing losses or for determination of a probable loss therein; and (e) For assessment of coma phases and cerebral (brain) death. These action potentials occurring at some centers (such as cochlea, cochlear nucleus, SOC, lateral lemniscus, inferior colliculus, medial geniculate body) included in the auditory system and producing action potentials are recorded by using superficial electrodes.

Electrodes are stuck around the head, and responses to sound given to ear are recorded. It is a test having an important role particularly in newborn hearing screening. It must absolutely be applied to infants who fail in auto-acoustic emission (OEA) test, being a screening test.