Multiple-frequency tympanometry in children with acute otitis media.

Multiple-frequency tympanometry (MFT) is a sweep-frequency method of acoustic immittance measurement, recently introduced in clinical practice. It provides values for the resonant frequency of the middle ear system. The purpose of this study was to use MFT to collect information about the mechanoacoustical changes occurring to the middle ear system after acute otitis media and to compare it with the results of conventional, low probe-tone tympanometry. Children with acute otitis media were followed up with both methods for 1 month after an episode of acute infection. Also, children with normal hearing were studied to establish normative data. Resonant frequency of the middle ear was found to be lower than normal even 1 month past the initial episode, for all types of 226-Hz tympanograms. MFT seemed to record changes in the middle ear after acute otitis media that 226-Hz tympanometry was unable to detect, implying persistence of pathology. More extended research will illuminate the clinical value of this method in the follow-up of acute otitis media.