One thing is for sure, Covid-19 is constantly changing and our information on the virus is constantly growing and evolving. As an audiologist, I am always looking at whether the hearing system is affected by other health conditions. This year, by self-report, I can say that I have seen more young people with the primary complaint of tinnitus come in for a hearing test than in previous years. In most cases, there have been other factors involved such as loud noise exposure but many of these clients did have Covid-19 at some point before they came to see me. I have also been asked more and more frequently if the tinnitus or hearing loss could have been caused by Covid-19 and whether receiving a vaccination would make it worse (more on that in another post). As a provider, I cannot confidently answer these questions. The only resources I have are scientific data that is currently available, and to tell you the truth, there is not much hard evidence out at this point. Tinnitus is a tricky thing to measure by nature, because it is a subjective measure, meaning that we have to rely on patient report rather than having an objective test to measure it. Hearing loss on the other hand can be measured objectively using pure-tones and speech.
Tinnitus is the sensation of noise in one or both ears that is usually only heard by the individual who is affected. The sensation of noise can be many things such as a ringing, buzzing, or roaring sound. Tinnitus can be mild or severe and affects different individuals in different ways. One person may just hear it in the background and not be bothered while another is so bothered by the sound in their ears that they seek emergency attention. Some known causes of tinnitus currently are hearing loss, history of loud noise exposure, blockage of the ear canal with wax, tumor on the auditory nerve, certain drugs, and injury to head or neck. At this point, there is no “cure” for tinnitus, rather we have techniques and tools to “manage” it. Research continues to be done on the subject but there is no straightforward understanding of all aspects of tinnitus.
In my quest to find solid scientific data about Covid-19 in relation to tinnitus I came across a systematic review, done by Kevin Munro, Ph.D., a professor of audiology at the UK’s Manchester Center for Audiology and Deafness. In this review, Professor Munro analyzed 28 case reports/series and 28 cross-sectional studies which met the inclusion criteria. Through these reports and studies, he found that there are multiple reports of hearing loss (e.g. sudden sensorineural), tinnitus and rotatory vertigo in adults having a wide range of Covid-19 symptom severity. The pooled estimate of prevalence based primarily on retrospective recall of symptoms, was 7.6% for hearing loss, 14.8% for tinnitus, and 7.2% for vertigo. This data was compiled in December of 2020 meaning it was based on initial variants of Covid-19 and before vaccines were widely available. It does give a nice estimate of whether Covid-19 was associated with hearing loss or tinnitus.
Looking at more recent data, it appears that there has not been another published study to determine the frequency of tinnitus associated with Covid-19 but the 15% marker for tinnitus as a side effect of Covid-19 does continue hold true based on patient reported side effects.
Even if there is a connection between Covid-19 and tinnitus, we still don’t necessarily know the precise cause. Tinnitus could be an indirect consequence of the virus, or it could be related to other things in life such as stress, lack of sleep, poor diet, or overall health. It is safe to say that many individuals have felt an increase in stress levels over the past two years since the pandemic started. Although not true for everyone, many individuals have also reduced exercise and changed their diet and neglected overall health due to fear of going to the doctor.
I do believe it is safe to say that current data leads us to the conclusion that tinnitus is a possible side effect of Covid-19 and could be around the prevalence mark of 15% of people affected. It is important to note that different variants of Covid-19 continue to produce different side effects so what may have been true with one may be different with another. It will be interesting in the following months and years to continue to track the pattern and draw new conclusions.