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

Abstract

Background:  This study evaluated the effects of coronavirus disease 2019 (COVID-19) on the cochlea and auditory efferent system with transient evoked otoacoustic emissions (TEOAE) and contralateral suppression (CS).

Objective:  We aimed to evaluate the pre- and post-COVID-19 TEOAE and CS 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 for COVID-19 as a within-subjects study design. All participants exhibited hearing thresholds below 25 dB HL at all frequencies and all participants demonstrated bilateral Type A tympanograms. The tests were performed in the linear mode using a double probe on the Otodynamics ILO292-II device. The CS of the otoacoustic emissions 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 (eight females and three males) aged between 20 and 35 years (mean age, 26 ± 3.66).

Data collection and analysis:  Wilcoxon signed rank test and Spearman's correlation test were used for statistical analysis using the Statistical Package for the Social Sciences 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 to 4000 Hz, 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 those before 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 with the premeasurement.

Conclusion:  The study findings show that severe acute respiratory syndrome coronavirus 2 can affect the cochlea and the auditory efferent system in adults. Post-COVID-19 audiological evaluation can also be considered part of a general medical examination.