What is Tympanometry?
Tympanometry provides a way, along with a physical exam, for doctors to diagnose and monitor problems with the middle ear. It can help with diagnosing disorders that can lead to hearing loss, especially in children.
The test measures your ear’s response to both sound and pressure. The results are recorded on a graph called a “tympanogram.”
The test can tell the doctor if you have:
- fluid in your middle ear
- otitis media (ear infection)
- a perforation (tear) in the eardrum
- a problem with the Eustachian tube (tube that links the upper part of the throat and nose with the middle ear)
To chronicle how much fluid a child has in their middle ear over time, typanometry can be performed every few weeks for several months.
How is Tympanometry Performed?
Before the test, your doctor may look inside your ear canal with a light to make sure there is no earwax or a foreign object obstructing your eardrum. Next, a probe-type device is placed into your ear canal. It may feel a little uncomfortable, and you will hear loud tones as the device begins to take measurements. This test changes the air pressure in your ear, making the eardrum move back and forth. The test measures the results on graphs called tympanograms.
You won’t be able to move, speak, or swallow during the test or it may give an incorrect result. If your child is having tympanometry, they may need to be shown how the test is done using a doll so they can prepare for the loud noises and practice being still beforehand. The test takes about two minutes for both ears. Anyone from infants to adults can have tympanometry, which usually takes place in a doctor’s office.
There are no risks during a tympanometry test.
Interpreting the Results of Your Test
When results are normal, there is no fluid present. Normal pressure inside the middle ear can vary between +50 to -150 decapascals. Decapascals (or daPa) are a measurement of air pressure. In a normal test result, the eardrum looks smooth. A normal tympanogram also shows normal pressure in the middle ear with normal movement of the eardrum and the conduction bones—these are bones that aid in hearing.
Tympanograms that show an abnormal result may reveal:
- fluid in the middle ear
- perforation of the tympanic membrane (tissue that separates the middle from the outer ear)
- scarring of the tympanic membrane (from frequent previous ear infections)
- middle ear pressure beyond the normal range
Tympanometry may also reveal:
- tumors in the middle ear
- earwax blocking the eardrum
- lack of contact between the conduction bones of the middle ear
- perforated eardrum
A tympanometry should be done in tandem with other, related tests if it’s being used to diagnose a condition, as it only really tests for problems with the middle ear. If your test results are abnormal, you will be sent for additional testing and a follow-up appointment with a specialist.