Tympanometric measures of eustachian tube function.

The purpose of this study was to develop instructions and procedures and to establish a normal data base for four tympanometric tests of Eustachian tube function: Valsalva, Toynbee, Inflation, and Deflation. Data were obtained for 24 young adults (48 ears) with normal hearing and normal middle-ear function. The tympanograms were analyzed for differences between baseline and experimental (postmaneuver) and baseline and posttest tracings for seven measures: tympanogram peak pressure, peak acoustic admittance, static acoustic admittance, negative gradient, positive gradient, and negative and positive acoustic-admittance values at +/- 400 daPa. The results indicated a statistically significant difference only in peak pressure for baseline and experimental tympanograms. Peak-pressure shifts were most pronounced for the Valsalva and Toynbee procedures. The small pressure shifts characteristic of the Inflation and Deflation procedures coupled with the potential for instrumental error severely limit the use of these procedures as means of obtaining reliable indices of tubal function.