A review on the impacts of COVID-19 on the auditory system: Implications for public health promotion research

Background: Currently, there are few studies on the relationship between COVID-19 and the auditory system. In the current study, a review of the studies conducted in the fields of etiopathology, clinical manifestations, research, and treatment of hearing loss caused byCOVID-19 was conducted, which can be used as a baseline for future studies. Methods: We utilized the research approach suggested by Arksey and O'Malley to carry out this scoping review. Search was conducted in Farsi and English with a focus on the onset of hearing loss in patients with COVID-19 through Medline and PubMed, and Google Scholar search engine. Studies included were those involving adult patients diagnosed with COVID-19 who experienced hearing loss, ear pain, ear discharge, and otitis media. Studies were eligible for inclusion if there was a description of the otologic dysfunction, specifically onset, duration, or clinical outcomes. Results: Among 90 studies identified, 35 studies were included in the review process. Our findings suggest several possible mechanisms for sudden sensorineural hearing loss (SSNHL) in COVID-19 patients, and COVID-19 infection could have deleterious effects on the inner ear, specifically on the hair cells of the cochlea despite patients being asymptomatic and early identification of SSNHL in COVID-19patients can save the hearing and also patient. Conclusion: Hearing loss in COVID-19 infection has not received much attention by health care professionals. Sensorineural hearing loss (SNHL), tinnitus, and/or vertigo have been shown to occur during and following COVID-19 infection. Due to lack of research studies, and the inconsistency and even contradictory of the findings, it remains questionable whether COVID-19 contributes to the high incidence of hearing loss. The proper understanding of the mechanisms behind hearing loss in COVID-19 infections needs further research. However, it seems likely that SNHL could be included among the manifestations of those-called "long COVID" syndrome.