A tympanometry is a test that measures how well the middle ear is functioning. The word "tympanometry" was formed from the combination of two Greek words. "Tympanon" means drum, and "metrein" denotes the act of measuring something. Prior to performing the test, a health care provider ensures that there are no obstructions in the path to the tympanic membrane, commonly called the ear drum. This is done simply by viewing the inside of the ear canal.
Usually, the test is carried out by a medical professional who places a hand-held device into the ear. The tool fluctuates air pressure inside of the ear canal, causing the drum to move back and forth. Results of the test are recorded on tympanograms, which are graphs that can be read after the procedure. Although health care providers generally state that there are no risks associated with a tympanometry, the test might be uncomfortable for some people. Children usually are more cooperative if they understand what to expect and how they should behave.
Typically, children younger than seven months are not subjected to a tympanometry because of behavior. Even if they are held still by a parent or guardian, fear might cause them to cry, fret or whine. The sounds produced by these reactions interfere with the changing air pressure in the ear canal and the movement of the drum. Accurate results, therefore, cannot be obtained with such interference.
During the test, the person undergoing the test might hear loud sounds. If he or she reacts with jerky movements, the results can be distorted. This is why such a procedure might prove impossible in very young children who don't understand the need to remain still. Often, the use of a doll to demonstrate to a child what will happen during a tympanometry and how he or she should behave is helpful.
There are important reasons why this test might be ordered by a health care provider. The presence of a tumor or fluid in the middle ear can be detected by the procedure. Impacted ear wax or a pierced or scarred ear drum also can be discovered with this test. A tympanometry, also known as a tympanogram, is not always an accurate way of discovering problems inside the middle ear.
There is a tube, called the eustachian tube, that connects the back part of the nose and the throat to the middle ear. This tube might not be functioning properly at the time of the test, for various reasons. If there is a problem with this tube, the ear drum typically will not move normally. Since its movement is what is measured during the procedure, the results can be misleading. There also have been cases in which a tympanometry indicated the presence of fluid behind the ear drum when there was none.