Tympanometry for Eustachian tube evaluation.

Abstract

Since Metz first suggested in 1946 that impedance measures may detect the status of the eustachian tube as a middle ear ventilator, only a few reports have appeared in the literature on this subject until just recently. This, in spite of the fact that the principle of tympanometry has been gaining a significant role in the differential diagnosis of middle ear pathology in the Scandinavian countries for the past dozen years. The availability of a commercial electro-acoustic impedance bridge was the impetus for a recent surge of interest in the concept of impedance audiometry in the United States. Tympanometry is the segment of impedance audiometry that consists of a graphic measurement of the ear drum's compliance during changes in static pressure in the external ear canal. It is a simple, quick procedure administered by nonmedical personnel on patients of all ages. It has the potential to serve as an adjunct to the diagnosis of eustachian tube insufficiency, to monitor treatment restoring adequate function, and, possibly, as a screening device to detect preclinical pathological conditions of the middle ear.