Despite ongoing research on COVID-19 (SARS-CoV-2), there is still so much to learn about its effects on the auditory system. Although rare, hearing loss or tinnitus has been cited as a complication of COVID-19 infection, meaning it's not part of the initial onset of symptoms but may develop days or weeks later.
8 Week Delay
According to a recent case study, one in ten COVID-19 patients report experiencing some form of hearing loss or tinnitus 8 weeks post infection.1
Research published in the International Journal of Audiology surveyed 120 patients in the U.K. who had been hospitalized for COVID-19. When the patients were asked if they had any changes in their hearing, 13% reported it being worse. Eight patients said their hearing had deteriorated and eight said they had tinnitus (ringing in the ears).2
Hearing Damage In Asymptomatic People
One recently published article in the American Journal of Otolaryngology, titled “Audiological profile of asymptomatic COVID-19 PCR-positive cases,” has concluded that COVID-19 appears to harm the hair cells and the cochlea even in asymptomatic individuals.3
Researchers have also pointed out that cochlear hair cells, which process sound vibrations, are “particularly vulnerable” to damage caused by restricted oxygen and blood supply ‒ two complications that have been reported in patients hospitalized with COVID-19.
Viral Infections And The Auditory System
It isn’t rare for a virus to affect the auditory system. Historically, Measles, Mumps, HIV and Congenital Cytomegalovirus have caused damage. Interestingly, none of the previously known Coronaviruses (SARS, MERS) have been shown to impact hearing.
A recent autopsy study conducted at Johns Hopkins School of Medicine, confirms the presence of the SARS-CoV-2 virus in the middle ear and mastoid.4
Could Hearing Loss And Tinnitus Be A Side Effect Of Medications?
Drugs prescribed to combat COVID-19, like remdesivir, hydroxychloroquine, lopinavir, and ritonavir, all have something in common ‒ they are ototoxic, meaning they can cause damage to the cochlea5.
Depending on the dosage and duration of use, these medications can have severe effects on the auditory system which may take weeks or months to notice.
More Research Is Needed
With the situation constantly evolving, more studies are needed to understand how the virus affects the ear and what exactly is causing hearing loss in COVID-19 patients. We may find that stress, anxiety, medications and overall poor health are more to blame.
Almufarrij I, Uus K, Munro KJ. Does coronavirus affect the audio-vestibular system? A rapid systematic review. International Journal of Audiology. 2020. 59:7, 487-491. doi:10.1080/14992027.2020.1776406
Munro, KJ, Uus K, Almufarrij I, Chaudhuri N, Yioe V. Persistent self-reported changes in hearing and tinnitus in post-hospitalisation COVID-19 cases. International Journal of Audiology. 2020. doi:10.1080/14992027.2020.1798519
Mustafa MW. (2020) Audiological profile of asymptomatic Covid-19 PCR-positive cases. Amer J Otolaryngol. 41(3):1-3.
Frazier KM, Hooper JE, Mostafa HH, Stewart CM. SARS-CoV-2 virus isolated from the mastoid and middle ear implications for COVID-19 precautions during ear surgery. JAMA Otolaryngology—Head & Neck Surgery. 2020. DOI:10.1001/jamaoto.2020.1922.
Ciorba A, Corazzi V, Skarżyński PH, et al. Don't forget ototoxicity during the SARS-CoV-2 (Covid-19) pandemic!. Int J Immunopathol Pharmacol. 2020;34:2058738420941754. doi:10.1177/2058738420941754