Objective assessment of autophony in patients with patulous Eustachian tube.

The objective of the present study is to evaluate the Eustachian tube (ET) acoustic patency during phonation. The sound level in the EAC during phonation of the "A" and "N" sounds was measured by microphones in the bilateral EACs of nine normal subjects and 31 patients with patulous ET. The measured sound pressure differences between the right and left ears were correlated with the differences in severity of autophony between the bilateral ears assessed by a visual analogue scale (VAS). The patulous condition was often remarkable when the "N" sound was phonated. In some patients with patulous ET, the patulous condition was indicated only by the present method, and not by conventional ET function tests such as tubo-tympano-aerodynamic-graphy or sonotubometry.