Reevaluation of the tympanometric findings in otitis media with effusion.

The charts of 1395 patients who underwent tympanometry at 56 otolaryngologic services in Shizuoka Prefecture were analysed. In more than 95% of the cases the diagnosis was otitis media with effusion (OME) and related conditions.1. Tympanometry is not essential for the diagnosis of OME, excluding cases of sen sorineural hearing loss or narrow external canal, though it can detect OME at a high rate.2. Tympanograms agreed well with the results of other objective tests, especially oto scopic findings.3. Rounded type (BR) tympanograms indicated the presence of fluid with a high prob ability as well as flat (BF) tympanograms. When BF type tympanograms are taken with a handy type of impedance audiometer, artifacts must be ruled out.4. A single tympanogram cannot provide the prognosis of OME.5. Tympanograms are useful in selecting therapeutic regimens and evaluating their effectiveness.6. The advantages and disadvantages of one's own impedance audiometer should always be kept in mind. If the results of tympanometry differ from other findings, one should be ready to retest tympanometry, especially when one uses a handy type of impedance audiometer.