Tympanomety from 200 to 2000 Hz probe tone.

Previous investigations have shown that the probe tone frequency is the main factor in determing the shape of the tympanogram. These had, however, been limited up to 800 Hz. In the present paper, a multifrequency investigation (from 200 to 2000 Hz) has been performed on 72 ears with different pathophysiological conditions of the middle ear. From the analysis of the result some new critical aspects of tympanometry emerge. The multifrequency tympanometric investigation proves to be, according to our experience, a far more sensitive method for checking small changes in the transmission characteristics of the tympano-ossicular system than the monofrequency traditional analysis. In this connection, the technique seems to furnish a simple and reliable method for discriminating between stiffness versus mass-controlled systems.