Assesment of Hearing Loss and Prognosis in Middle Ear Ventilation Disorders Based on Otoacoustic Emissions

Objectives: Aims of the study was to establish the relationship between the hearing level (HL) and OAE's response in MEVDs. Further more to asses the prognosis of the disease by pretreatment and post treatment observations done at 1st and 2nd month. Background: Because otoacoustic emissions (OAEs) are transmitted from the cochlea to the ear canal via the middle ear, OAEs are directly influenced by the transmission properties of the middle ear. In general, Middle ear ventilation disorders (MEVDs) reduce the measured emission amplitudes and sometimes eliminate the response entirely. Material and Methods: A study group of 97 ears was formed which was divided further to controls and cases groups of 36 and 61 patients respectively, based on signs and symptoms along with otoscopy, tympanometry and pure tone audiometry (PTA) examination. Then OAE test with preset protocols was done for both DPOAE and TEOAE. Results: A depressed level of OAE was found in the pretreatment study group, which improved with increased signal to noise ratio (SNR) level after the treatment. Conclusion: The OAE (TEOAEs and DPOAEs) are highly reliable, objective and noninvasive useful tests for assessing HL, in predicting the course and monitoring changes in MEVDs.