Otology Fellowship is now available
"Otology Fellowship Program" at Karnataka ENT Hospital & Research Center (R)
Impedance Audiometry Test
Impedance Audiometry Test is available at Karnataka ENT Hospital and Research Center (R).
Overview
Tympanometry also know as acoustic immitance test is an examination used to test the condition of the middle ear and mobility of the eardrum ( tympanic membrane ) and the conduction bones by creating variations of air pressure in the ear canal.
Tympanometry is an objective test of middle-ear function. It is not a hearing test , but rather a measure of energy transmission through the middle ear. The test should not be used to assess the sensitivity of hearing and the results of this test should always be viewed in conjunction with pure tone audiometry .
Test Parameters
Tympanometry is a valuable component of the audiometric evaluation. In evaluating hearing loss, tympanometry permits a distinction between sensorinueural and conductive hearing loss, when evaluation is not apparent via tuning fork testing (Weber and Rinne testing).
After an otoscopy (examination of the ear with an otoscope) to ensure that the path to the eardrum is clear and that there is no perforation, the test is performed by inserting the tympanometer probe in the ear canal. The instrument changes the pressure in the ear, generates a pure tone, and measures the eardrum responses to the sound at different pressures.
Type A tympanogram is considered normal. There is a normal pressure in the middle ear with normal mobility of the eardrum and the conduction bones.
Type B and 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.