The Tympanogram: What It Is
Tympanometry is a remarkably quick and non-behavioural method that almost instantly assesses the status of the middle ear. It tells a lot of information in a very short amount of time. As children are more susceptible to Otitis Media (OM), pediatricians very commonly rely on the use of tympanometry. Of course, tympanometry is also useful for differential diagnosis, because normal tympanometric results help rule out middle ear pathology.
With a normal, healthy middle ear, air pressure is even on both sides of the eardrum or tympanic membrane (TM). When there is no vacuum or fluid build-up behind the TM, the middle ear is most efficient at allowing incoming sounds to pass through it. This is the main assumption behind Tympanometry. Unlike pneumatic otoscopy, tympanometry does not determine “how much the TM wiggles.” Instead, it looks at how much sound is passing through the TM, while the air pressure in the ear canal is changed from positive, to normal, to negative.