The Investigate of Middle Ear Disorders and Hearing Loss Due to Them on Transient Evoked Otoacoustic Emissions and Distortion Product Otoacoustic Emissions.

Objective: To investigate the effects of middle ear pathologies on transient evoked (TEOAE) and distortion product otoacoustic emissions (DPOAE), to compare pre- and posttreatment TEOAE and DPOAE responses in medically or surgically treated cases, and to reveal correlations among the results of conventional audiologic and otoacoustic emission tests. Materials and methods: One hundred and seven ears of 62 patients with hearing loss due to middle ear pathologies were included to this study. Otitis media with effusion was diagnosed in 31 patients (61 ears), chronic otitis media in 18 patients (22 ears), adhesive otitis media in seven patients (10 ears) and otosclerosis in nine patients (14 ears). In two cases, chronic otitis media in one ear and adhesive otitis media in the other ear was observed. Pure tone and speech audiometric tests, impedence audiometric test, TEOAE and DPOAE tests were carried out. Patients having otitis media with effusion were followed by using medical treatment. Ventilation tubes were inserted to 12 patients who had not responded to medical treatment. In those patients, audiometric and otoacoustic emission tests were repeated. Results: A poor correlation was observed between the pure tone averages and the TEOAE values obtained on the f？rst examination (r= 0.469, p= 0.00). A poor negative correlation was observed between the pure tone averages and the DPOAE values that were measured in 1500 Hz, 2000 Hz, 3000 Hz, 4000 Hz, 6000 Hz. r and p values were -0.356 and 0.000 for 1500 Hz; -0.305 and 0.001 for 2000 Hz; -0.427 and 0.000 for 3000 Hz; -0.238 and 0.014 for 4000 Hz; -0.470 and 0.000 for 6000 Hz. We din’t find any correlation between the pure tone avereges and the DPOAE values at 1000 Hz (r= -0.180, p=0.064). There was no correlation in the DPOAE values between the 1000 Hz and the other frequencies. It was observed that other frequencies were correlated poorly with each other (1500 Hz, 2000 Hz, 3000 Hz, 4000 Hz, 6000 Hz). Before medical or surgical treatment, 7 % of patients having otitis media with effussion had complete TEOAE response. After medical or surgical treatment, the proportion of complete response was increased to % 41. In these cases, DPOAE responses and amplitudes were increased after treatment. Conclusion: Although DPOAE gives more reliable results in high frequencies, it is of little benefit in the clinical evaluation in the low frequencies especially at 1000 Hz. Abnormal pressures and pathologies in the middle ear decreased OAE responses and the responses were increased after appropriate treatment