There have been several pathophysiological processes proposed regarding how audiovestibular disorders are caused by COVID-19. Viral involvement can cause cochleitis or neuritis of the inner ear or auditory nerve. Antibodies or T-cells could damage the ear if they mischaracterized inner ear antigens as the virus. Sudden hearing loss may also be a result of cochlear ischemia or hypoxia, due to the cardiovascular abnormalities associated with COVID-19. Finally, the virus may trigger immune-mediated inflammation that causes hearing loss, such as inflammation of the meninges.
There are published case studies that cite COVID-19 as the reason for a sudden sensorineural hearing loss (SSNHL). Sudden sensorineural hearing loss is when there is a change in hearing because of an issue in the inner ear (the cochlea) or the nerves beyond that which happens within a very short time.
The most common cause of sensorineural hearing loss is natural aging, and that happens as the cochlear hair cells degrade over time, usually several years. When that happens, you slowly lose sensitivity to sound and have a more difficult time hearing as clearly. The other most common cause of hearing loss is due to loud noise.