A search for the most suitable imminent components and probe tone frequency in tympanometry.

The relative occurrence of bell-shaped and various types of W-shaped susceptance-conductance and admittance-phase tympanograms at a probe-tone frequency of 660 Hz was determined from registrations on normal ears. The diagnostic value of the susceptance-conductance versus the admittance-phase representation of tympanograms was studied on pathological middle-ear systems. Using probe-tone frequencies from 510 Hz up to 910 Hz, tympanograms for all four imminent components were recorded on 10 pathological ears and the diagnostic value compared. From the combination of these studies we conclude that the admittance-phase approach at a probe tone frequency between 500 and 700 Hz is a good choice.