Mounting evidence is showing that COVID-19 may have some link to tinnitus, hearing loss, and vertigo.
In a new study, published this week in the International Journal of Audiology, researchers at the University of Manchester and Manchester Biomedical Research Centre in the UK carried out a systematic review of dozens of studies investigating the link between COVID-19 and auditory symptoms.
Among people who were infected with COVID-19, around 7.6 percent suffered from hearing loss and 14 percent experienced tinnitus, a persistent ringing or whooshing sound in the ears. A further 14.8 percent of people also reported vertigo, a dizzy sensation that everything is spinning around you. This sensation is usually caused by a problem with your inner ear, as this is the HQ of the vestibular system responsible for balance.
“There is an urgent need for a carefully conducted clinical and diagnostic study to understand the long-term effects of COVID-19 on the auditory system,” Kevin Munro, Professor of Audiology at The University of Manchester and Manchester BRC Hearing Health Lead, said in a statement.
Why COVID-19 affects the auditory system in this way remains unclear. It may be that SARS-CoV-2, the virus that causes the disease, is directly damaging the tissues involved in the auditory system. After all, it’s known that COVID-19 is much more than a simple respiratory disease and can lead to damage to many major organ systems, including the liver, kidney, heart, and even the brain. The auditory system, it seems, may be no different.
“It is also well-known that viruses such as measles, mumps and meningitis can cause hearing loss; little is understood about the auditory effects of the SARS-CoV-2 virus,” adds Munro.
Alternatively, the researchers speculate on the idea that stress may have played a role in some of these complications. Writing in the Conversation, Professor Munro notes that tinnitus has a strong link with stress and anxiety. As plenty of studies have shown, the COVID-19 pandemic has taken a toll on mental health in many parts of the world. There’s also evidence to suggest that people who have caught COVID-19 are also at a heightened risk of anxiety, depression, or insomnia after recovery.
While it’s clear there is some link between COVID-19 and damaging effects on the auditory system, the researchers stressed that the nature of this association remains unclear. Like many aspects of the unfolding pandemic, further research is needed before any sturdy conclusions are reached.
“Though the evidence is of varying quality, more and more studies are being carried out so the evidence base is growing. What we really need are studies that compare COVID-19 cases with controls, such as patients admitted to hospital with other health conditions,” adds Ibrahim Almufarrij, PhD student and study author.
“Though caution needs to be taken, we hope this study will add to the weight of scientific evidence that there is a strong association between Covid-19 and hearing problems.”