[Evoked oto-acoustic emissions in patients with secretory otitis media]

In many studies, Evoked Otoacoustic Emissions (EOAEs) have been routinely documented in subjects with normal middle ear function showing tympanogram (TG) A type. However, middle ear dysfunction may influence the measurements of EOAEs. We investigated the EOAEs in ears with secretory otitis media (SOM) in order to understand the effects of middle ear dysfunction on EOAE measurements. We present data from 73 SOM ears of 38 subjects aged 3 to 58 (mean = 9.4 years) and data from 61 ears of 54 subjects with sensorineural hearing loss as a control. Generally, the EOAE thresholds of ears with mild sensorineural hearing loss have a good correlation with the audiometric hearing threshold level. On the other hand, the EOAE thresholds of ears with SOM were on the average higher than those expected from the audiometric hearing threshold level. In this paper, we classified TG B type further into TG B1 type and TG B2 type according to our criteria. Though neither TG B1 type nor TG B2 type revealed peaks in the tympanogram (-300mmH2O < or = < or = 200mmH2O), the 2 groups differ in that TG B1 type seems to have its peak at pressures under -300mmH2O on tympanography while TG B2 type seems to have no peaks in that pressure range. As a consequence of this classification, most of the EOAE thresholds of SOM ears showing TG B2 type were scaled out (> or = 40 or 50 dB nHL).(ABSTRACT TRUNCATED AT 250 WORDS)