A New Test of Eustachian Tube Function with Otoadmittance Meter: Tubotympanometry

Abstract

A new method for testing Eustachian tube function using an otoadmittance meter (Tubotympanometry) is reported. the otoadmittance meter is set for the aural reflex test, namely in the position of Y-T recording. the patient is asked to carry out deep breathing, Valsalva's ma-neuvre, normal breathing, and swallowing in succession. in normal 40 ears, three types of the tubotympanogram were classified. in type A, observed in 32 ears, the graph shows no changes during deep breathing, a sudden downward deflection with Valsalva's maneuvre, a return to a level after the maneuvre and on repeated swallowing the graph returns to the initial level in stepwise. in type B, observed in 5 ears, the graph returns to the initial level directly after Valsalva's maneuvre without swallowing. This indicates a slightly patent tube, even though in the normal range. Type C was observed in 3 ears of patients who failed to perform Valsalva's maneuvre correctly. in the case of a patent tube, the graph shows a remarkable fluctuation synchronizing with inspiration and expiration. in the case of an occluded tube, the graph shows slower recovery after Valsalva's maneuvre and no complete return to the initial level even after repeated swallowing. in another case of occluded tube, the graph was deflected upward by Valsalva's maneuvre and showed no change on deglutition. the greatest advantage of this test is the simplicity of the equipment and of the test procedure.