A tympanogram, also known as tympanometry, is a testing methodology to examine how well the middle ear works. To perform a tympanogram, a health care provider, usually an ear doctor, places a probe inside the ear that alters air pressure and causes the eardrum to vibrate. The results help determine if the eardrum is perforated, if there is fluid in the ear, and if the middle ear system is working properly. The test can be done on patients of all ages.
The results are recorded on a chart produced by a machine called a tympanometer, which tests the eardrum's ability to reflect sound. A person's eardrum, also known as the tympanic membrane, is flexible. The greater the ability to reflect sound generally indicates greater mobility.
While the tympanogram is being performed, a person is often asked to lie still and refrain from speaking or swallowing. Any such movement can alter the pressure in the middle ear and could result in an inaccurate result. To perform the test, a person's ear must be free of debris and requires a tight seal between the tip of the probe and the ear. During the tympanogram, a patient will hear tones that may be loud, and the probe may cause discomfort. The time required to perform the test is generally less than two minutes.
A tympanometer is a handheld probe that is placed in the ear. The probe consists of tubes that include a speaker, a microphone, and a pump. When the instrument is placed in the ear, it creates an airtight seal against the inner ear wall. A tone is sent through the speaker as the pressure changes within the sealed channel. The microphone records the amount of sound that is repeated during the test and the data is recorded on a graph.
Tympanogram information is data driven and does not require a response from a patient. Insights about the ear that can be learned from the test include tympanic membrane movement and middle ear pressure. The results of a tympanogram are plotted on a graph and labeled as Type A, B, or C.
If a patient's result falls into Type A, the movement of the tympanic membrane is considered normal. A type B reading is often a sign of minimal or no tympanic membrane flexibility, often requiring medical treatment. A Type C result may indicate a negative pressure tympanic membrane. This tympanogram reading may be the result of tympanic membrane retraction or obstruction in the Eustachian tube.