The Effect of COVID-19 on the Efferent Auditory System in Adults

Abstract

Background: It was evaluated the effects of COVID-19 on the cochlea and auditory efferent system with Transient Evoked Otoacoustic Emission (TEOAE) and Contralateral Suppression (CS) Test in this research. Purpose: We aimed to evaluate the pre- and post-COVID-19 Transient Evoked Otoacoustic Emission and Contralateral Suppression results in the same participants to reveal the effect of COVID-19 on the efferent auditory system. Study Design: The CS measurement was performed twice for each participant before a diagnosis of COVID-19 and after treatment of COVID-19 as a within-subjects study design. All participants had normal hearing at all frequencies (≤ 25 dB HL at 0.25 – 8 kHz) and had normal middle ear functions in both ears. The tests were performed in the linear mod by using double-probe on the Otodynamics ILO292-II device. The CS of the OAEs was measured at 65 dB peSPL TEOAE stimulus and 65 dB SPL broadband noise. All parameters including reproducibility, noise, and stability were considered during the measurements. Study Samples: The study included 11 patients [8 female and 3 male] aged between 20 and 35 years (mean age is 26 ± 3.66). Data Collection and Analysis: Wilcoxon Signed Ranks Test and Spearman's correlation test were used for statistical analysis via Statistical Package for the Social Sciences (SPSS) version 23.0. Results: The Wilcoxon Signed Rank Test showed that there was no significant difference between the pre-and post-COVID-19 TEOAE CS results in all tested frequencies and measurement parameters, 1000 Hz to 4000 Hz, respectively Z= -0.356, -0.089, -0.533, -0.533, -1.156 and p<0.05. Although not statistically significant, the CS results obtained post-COVID-19 at all frequencies except 4000 Hz were lower than that pre- COVID-19. According to the overall TEOAE results after COVID-19, a statistically significant decrease was observed at 3000 Hz (Z=-2.847, p<0.01) and 4000 Hz (Z=-2.401, p<0.05) compared to the pre-measurement. Conclusions: The study findings show that SARS-CoV-2 can affect the cochlea and the auditory efferent system in adults. Post-COVID-19 audiological evaluation can also be considered part of the general medical examination. Key words: Covid-19, SARS-CoV-2, efferent system, contralateral suppression, otoacoustic emission