Audiological Profile of Asymptomatic COVID-19 PCR-Positive Cases
Despite ongoing research on COVID-19, there is much to learn about its effects on the auditory system in individuals who are symptomatic and asymptomatic.
In a recent article, Mustafa (2020) examined the impact of COVID-19 on the auditory system in 20, 20- to 50-year-old adults, who were confirmed positive for COVID-19, asymptomatic, and had no history of hearing loss.
The experimental and a control group of 20 subjects completed an otological examination, basic audiological evaluation, immittance evaluation, and transient-evoked otoacoustic emissions (TEOAEs).
Pure-tone hearing threshold results suggested no significant differences between the experimental and control group at low- and mid-octave frequencies, but a significantly poorer thresholds were found for the experimental group in the high frequencies (4000, 6000 and 8000 Hz). Additionally, a significant group difference was detected for the TEOAE results, with amplitudes significantly worse in the experimental group.
Mustafa concludes by discussing how COVID-19 appears to harm the hair cells and the cochlea even in asymptomatic individuals. However, future results will need to replicate these results with an age-matched control group.
Unfortunately, the study also suffered from numerous design flaws that limit interpretation: lack of baseline testing; control group was not randomized and limited to normal hearing participants with thresholds < 15 dB HL; and no adjustment for age, sex, or other confounding variables in the statistical methods.
Further, the differences in thresholds were within test-retest reliability, and TEOAEs showed only a 1.3 dB SPL difference between groups. Future work incorporating stronger study design will be helpful in delineating the relationship between COVID-19 and audiological implications.
Mustafa MW. (2020) Audiological profile of asymptomatic Covid-19 PCR-positive cases. Amer J Otolaryngol. 41(3):1-3.