Objective hearing testing
These methods for detecting hearing loss require no cooperation from the patient. For this reason, objective listening tests are very useful for the study of newborns and infants.
Otoacoustic emission (OAE)
This test reliably determines whether a person’s hearing is healthy or whether the inner ear is damaged.
A probe that emits certain sounds, is inserted into the ear. The inner ear responds to the signals and transmits an acoustic response that can be measured by the probe. This is typically used as a screening tool for hearing impairment most oftenly used with newborns.
Brainstem Evoked Response Audiometry (BERA)
Should hearing impairment be suspected in the auditory nerve or even in deeper areas of the brain the doctor will recommend BERA.
For brain stem audiometry, an acoustic stimulus is supplied. Head-mounted electrodes measure the electrical impulses of the auditory nerve. Abnormalities shown give an indirect indication of a possible disease of the auditory pathways in the brain.
This test also serves as evidence of other neurological diseases, that may result in a loss of hearing.
Stapedius reflex test
In this test the ear is subjected to a loud noise. In healthy ears it results in the contraction of both middle ear muscles that leads to a stiffening of the eardrum. This tension can be measured and an unexpected value can indicate damage to the middle ear.
A tympanometer simultaneously changes and measures the pressure in the middle ear. An acoustic stimulus is supplied at varying levels of pressure. The physician is then able to assess, among other things, the functioning of the eardrum, and determine if there is fluid present in the middle ear.
Tympanometry is not able to determine the extent of hearing loss.