[Transitory evoked otoacoustic emissions in children with impaired middle ear ventilation]

Transient evoked otoacoustic emission (TEOAE) has proven to be a useful clinical screening test for auditory dysfunction. Problems concerning the evaluation are mainly due to irregularities of the physiological middle ear functions. In this study different degrees of middle ear alterations were quantified by means of tympanometry, otoscopy and pure-tone audiometry and then related to the results of TEOAE registration which were classified by the coefficient of the cross correlation and the frequency response spectrum. Data were obtained from 82 ears of 41 children between the age of 3 and 7 years. When children displayed a tympanogram with no observable peak, a successful registration of TEOAE was possible in only 10.5% (n = 19) of the cases. Such results are related to serous or mucoid effusions which probably prevent a transmission of the emission from the cochlea to the meatus. In analysing the related between conductive losses in pure-tone audiometry and TEOAE it was demonstrated that no TEOAE was could be recorded in ears with a conductive loss above 20 dB HL. This study emphasizes the need to reexamine children who do not show positive emissions connected with middle ear imbalances. Only by retesting these children is it possible to determine whether or not cochlear lesions or middle ear problems prevent a positive TEOAE registration.