Tympanometry

Tympanometry is an objective examination used to test the condition of the middle ear and mobility of the eardrum (tympanic membrane) and the middle ear bones, by creating variations of air pressure in the ear canal.

The test is performed by inserting a device in the ear canal that will change the pressure in the ear, produce a pure tone, and measure the eardrum responses to the sound and different pressures. Results are shown in a curve called: Tympanogram.

Type A tympanogram is considered normal, that means that there is a normal pressure in the middle ear with normal mobility of the eardrum and the conduction bones. Type B or C tympanograms may reveal fluid in the middle ear, scarring of the tympanic membrane, lack of contact between the conduction bones of the middle ear or a tumor in the middle ear.

Tympanometry itself is not a hearing test but is a valuable component of the audiometric evaluation. In some cases it can give an idea of what type of hearing loss is suggested.

A Tympanometer (the device used to do tympanometry) often includes other tests as Acoustic Reflex (AR), Reflex Decay and Eustachian Tube Function (ETF).

If a loud sound is presented to the ear a muscle which runs through the middle ear and connects to the middle ear bones contracts and the middle ear bone chain becomes stiff. The acoustic reflex test can help to evaluate the degree of a hearing loss and/or find out the location of the hearing problem. It is also part of the identification process of Central Auditory Processing Disorders.

The Reflex Decay determines for how long the Acoustic Reflex continues. It can be used to find out if an auditory nerve disorder is present.

The Eustachian Tube connects middle ear and throat and has the purpose of pressure equalization and ventilation of the middle ear. The ETF can be used to find out if the Eustachian Tube functions normally.