Evaluation of noninvasive eustachian tube function tests in normal adults.

A causal association between eustachian tube (ET) dysfunction and otitis media (OM) has been documented. We present normative data for eustachian tube function (ETF) in an otologically normal population of 107 college-age subjects using two noninvasive methods: nine-step tympanometric testing and sonotubometry. The results show a 78% agreement between the two methods when one test session was performed. The nine-step test showed a 52% repeatability rate on three sequential test sessions while the sonotubometry test showed a 34% repeatability rate. The combined tests showed a 34% agreement for the three sequential tests. The findings reveal that the combination of the two tests identify 96% of normal subjects as having at least some tubal function present. Although both tests provide similar information regarding the presence of tubal opening, the sonotubometry method is more physiologic. Additional information shows that the average category of the nine-step test in a normal population was category 2, the mean duration of tubal dilation was 0.40 seconds, and the mean middle-ear pressure was -12 mm H2O.