Tympanometry

Tympanometry can help diagnose disorders that can lead to hearing loss, especially in children. The test measures the movement of your tympanic membrane in response to changes in pressure.

The tympanic membrane is a thin tissue that separates the middle and outer segments of the ear. The results of tympanometry are recorded on a graph called a tympanogram.

The test can help your doctor determine if you have:

• fluid in your middle ear
• otitis media (a middle ear infection)
• a perforation (tear) in the tympanic membrane
• a problem with the eustachian tube, which links the upper part of the throat and nose with the middle ear

Your child’s doctor may perform tympanometry every few weeks for several months to chronicle how much fluid your child has in their middle ear over time.

There are no risks related to the tympanometry test.

Before the test, a primary care doctor may look inside your ear canal with a special instrument called an otoscope. This is to make sure there’s no earwax or a foreign object obstructing your ear canal.

Next, they’ll place a probe-type device in your ear canal. It may feel a little uncomfortable, and you may hear loud tones as the device begins to take measurements.

This test changes the air pressure in your ear to make the eardrum move back and forth. Measurements of the movement of your eardrum are recorded in a tympanogram.

You won’t be able to move, speak, or swallow during the test. If you do, it may give an incorrect result.

The test takes about two minutes or less for both ears and usually takes place in a doctor’s office. People of all ages can have tympanometry, though it can be more difficult for children who are too young to cooperate.

If your child is having tympanometry, you may need to show them beforehand, by using a doll, how the test will be done. This can help them to prepare for loud noises and to practice being still.

Normal tympanometry test results mean:

• There’s no fluid in the middle ear.
• The eardrum moves normally.
• There’s normal pressure in the middle ear.
• There’s normal movement of the ossicles (the small bones of the middle ear that conduct sound and aid in hearing) and the eardrum.

Normal pressure inside the middle ear can vary between +50 to -200 decapascals (daPa) for both children and adults. (A daPa is a unit of air pressure.)

Abnormal tympanometry test results may suggest:

• fluid in the middle ear
• perforation of the eardrum (tympanic membrane)
• scarring of the eardrum, which usually results from frequent ear infections
• middle ear pressure beyond the normal range
• growths in the middle ear
• earwax blocking the eardrum
• lack of mobility or other problems with the ossicles of the middle ear

Tympanometry only really tests for signs that there may be problems with the middle ear. Fluid in the middle ear is by far the most common cause of an abnormal tympanogram. Other tests may also need to be performed to diagnose an ear condition.

If your test results are persistently abnormal, or your doctor suspects that something other than fluid is behind the tympanic membrane, they may send you for additional testing and a follow-up appointment with a specialist.