Otoacoustic emissions – Distortion product: study of different relations of sound levels on the test in individuals with and without hearing losses

Abstract

As a part of the audiological test battery, otoacoustic emissions can provide useful information for the management of hearing impaired patients. Objective: The aim of this study was to compare different stimulus levels in the test of Distortion Product Otoacoustic Emissions (DPOAE) in normal hearing and hearing impaired subjects. Method: Eighty subjects (160 ears) with normal hearing (group 1) and eighty utilizanine (135 ears) subjects with sensorial neural hearing loss (induced by occupational noise exposure) participated in this study. Results: The prevalence of present response in DPOAE was 70% in Group 1 and were not observed significant statistically differences between test with L1 = L2 = 70 dBSPL and L1 = 65 and L2 = 55 dBSPL. In Group 2 the prevalence of present response with L1 = L2 = 70 dBSPL was higher than L1 = 65 and L2 = 55 dBSPL but statistic analysis showed higher Spearman correlation between DPOAE responses and hearing thresholds with L1 > L2. Also the relation with gender, age and time of noise exposure were higher with L1 > L2. Conclusions: These results suggest that DPOAE with L1= 65 and L2= 55 dBSPL can be used to provide information in normal hearing and hearing impaired subjects.