Tympanograms obtained with probetone frequencies of 220 Hz and 800 Hz were compared in 1,143 ears with varying types and degrees of hearing disorder. In 141 of these ears, the tympanogram was normal at 220 Hz but showed a W pattern at 800 Hz.
Efforts to identify this result with a unique clinical entity or meaningful constellation of entities were unsuccessful. The W pattern at 800 Hz was observed in ears with almost every type of middle ear disorder and in normal ears as well. The occurence of the W pattern seems most closely related to disease of the tympanic membrane, but may also be a normal variant. Clinical impedance audiometry does not appear to derive substantial clinical benefit from tympanometry at a probetone frequency of 800 Hz.
Alberti PW, Jerger JF. Probe-Tone Frequency and the Diagnostic Value of Tympanometry. Arch Otolaryngol. 1974;99(3):206–210. doi:10.1001/archotol.1974.00780030214012
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