Evaluation of cochlear function in patients with tinnitus using spontaneous and transitory evoked otoacoustic emissions.

Abstract

Objective: The aim of this paper has been to investigate the cochlear function and the basic properties of otoacoustic emissions (OAEs) in patients with tinnitus using Spontaneous Otoacoustic Emissions (SOAEs) and Transitory Evoked Otoacoustic Emissions (TEOAEs).

Materials and methods: We have analyzed the incidence, amplitude and spectral content of hearing thresholds, SOAEs and TEOAEs in a sample of 44 ears. We have measured incidence, intensity, frequency, number of peaks and amplitude of emission and their variability across frequency range from 500 to 5000 Hz. A correlation was determined between the OAEs results and the results obtained using hearing thresholds.

Results: We have not found statistically significant differences at 500, 1000, 2000, 4000 and 8000 Hz frequencies neither at mean hearing thresholds between the sample of ears with tinnitus and the sample of ears without tinnitus. SOAEs were only present in 1 of the 44 ears tested (2.27%) and it was a 17 dB SPL amplitude peak at 2770 Hz frequency. TEOAEs, however, were displayed in some frequency in all the ears. We have compared TEOAEs parameters between the sample of ears with tinnitus and the sample of ears without tinnitus in 500, 1000, 2000, 4000 and 5000 Hz frequencies, and we have only found statistically significant differences at 4000 Hz, p = 0.02. Comparison of TEOAEs parameters between ears with tinnitus and ears without tinnitus in the same patient have only found statistically significant differences at 4000 Hz frequency, p = 0.011. In both cases there were not statistically significant differences at 500, 1000, 2000 and 5000 Hz frequencies nor at mean TEOAEs amplitudes for every group.

Conclusions: We have not found significant relations between tinnitus and OAEs registration.