Multifreuuency Tympanometry in Normal Hearing

Abstract

Tympanometry performed using a low probe tone frequency has proven its validity in identifYing a variety of middle ear disorders (e.g. effusion or abnormal air pressures within the middle ear cavity), tympanic membrane abnormalities (e.g. atrophic scarring, retraction or perforation) and Eustachian tube malfunction (Lilly, 1984). However standard low frequency tympanometry often fails to distinguish normal middle ears from ears with pathologies that affect the ossicular chain . (Shahnaz and Polka, 1997).

The multifrequency tympanometric investigation proves to be a far more sensitive method for checking small changes in the transmission characteristics of the tympano-ossicular system than the monofrequency traditional analysis (Valvik et aL, .1994).