A link between COVID-19 and sudden hearing loss has begun to emerge. In this episode of the Hearing Tracker Podcast, we speak directly with leading researchers to gain a better understanding of the connection. We also chat with someone who experienced a sudden hearing loss first-hand.

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Podcast transcript

Steve Taddei: Late in 2019, the unthinkable happened, and a coronavirus called SARS-CoV-2 swept the globe, changing our lives forever. In the US, we have seen roughly 40 million cases, and worldwide, nearly 3 million people have lost their lives to SARS-CoV-2.

The symptoms and impact felt by those who contract COVID-19 vary greatly. And a trend has begun emerging, suggesting that there may be a link between COVID-19 and hearing loss. In this episode, we'll explore this relation and reveal what the research has suggested so far. We'll also hear from someone who experienced a sudden sensorineural hearing loss and review what should be done if this happens to you?

Antonio: So it started off in the gym normal day, working out ...

Steve Taddei: That's Antonio, and he shared a rather shocking story with me from his early twenties.

Antonio: I believe I was on like the Smith machine, just doing bench press and had my in-ear headphones in. I can remember that clear as day. Got done, got off. I remember seeing a friend of mine out there, so I took my headphones off to talk to him. And right then I knew something was a little bit off. Couldn't tell exactly what it was, but it's something just did not seem right at all.

Let the day go on, went home was fine. But when I woke up that morning, I had complete hearing loss, nothing at all, no sound or anything. It was just like ... silence.

Steve Taddei: Antonio had experienced a sudden sensorineural hearing loss and it affects roughly one in 5,000 people every year as a result of an issue occurring within our inner ears.

Antonio: And then went to class, had a test that day, and I remember as soon as I got to class to take the test, that's when everything kind of went astray because I started getting really bad vertigo. I felt very sick. I never knew what vertigo was. I found out real quick what it was at that point. The room was spinning. Everything was spinning. I was taken to the doctor. Even in the car, it was magnified beyond belief.

When they examined it, she had looked in my ear, took the normal test that they normally do. And she said that it was just a ear infection. So gave me the general steroid that they would give probably I'm assuming everybody. And then just sent me on my way.

Steve Taddei: People with a sudden sensorineural hearing loss can experience symptoms such as fullness in their ears, tinnitus - or ringing, vertigo as Antonio experienced, where it feels as though the room is spinning around you, and an overall decrease in hearing. This can occur in one or both ears. Unfortunately, these symptoms are associated with other more benign issues, such as a common ear infection. As a result, it's possible for the true underlying issue to be overlooked and then mistreated.

Antonio: It prolonged for, I think it was two weeks to a month and I still didn't have anything back. Still everything was still not right. So I finally saw my actual physician at the time and he's like, he looked at my ear, did his exams, and he just like looked at me and said, you need to go see a professional, like, you know, basically right away. But he did give me an injection in the ear as like a last resort attempt to try to, you know, save it. He had said that if I'd come in sooner, it probably would've been better results, had I been given the right diagnosis at the time.

Steve Taddei: That last part was really important to note. Misdiagnosis and delayed treatment happen more often than you might expect. And while some sudden hearing losses spontaneously recover, it's rare. In around 90% of these losses, it's hard to tell what's affecting our auditory system. It can be an auto-immune disease, infections, blood circulation problems, or other disorders within our inner ear. And this is why we use steroids. They will hopefully reduce any inflammation and have a homeostatic effect. Ultimately this aims to reduce any longterm damage to our hearing.

So if treatment occurs several weeks later, like it did for Antonio, the benefits of treatment drop significantly, because the damage has already occurred.

So what does this have to do with COVID-19 and what we've been dealing with the past year? Well COVID-19 is a viral infection that affects our respiratory system. It can also cause a strong immune response as our bodies try to fight it. If you recall, these were a few of the issues that can cause a sudden hearing loss. Furthermore, some people have noted a change in their hearing or tinnitus following a COVID-19 related hospitalization. These are just a few of the reasons why scientists are looking into the possible connection between COVID-19 and hearing loss.

Francisco Alves de Sousa: It's very possible that SARS-CoV can affect the inner ear.

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Steve Taddei: That's Dr. Francisco Sousa. He is an ENT resident in Portugal. He's been working tirelessly to fight COVID and help his patients since the beginning of this pandemic.

Francisco Alves de Sousa: When I knew I was going to actually help to treat symptomatic counterparts positive for COVID-19, I felt it would be maybe a good idea to check those patients who had actually a severe or moderate-severe illness. Before I started to do the study was many anecdotal reports on episodes of sudden hearing loss. Like someone that's doing fine and doing good, and suddenly, from one ear, from both ears, they just go auditory deficit. Our study was in line with what was described in the asymptomatic patients. Our results show there was not a big, big, big difference, but there was a difference, especially in the, in the high frequency range. From 4,000 to 6,000 and 8,000, it was the worst difference, but actually the difference started from 1000. When you go to 2000, 3000, 4,000, up to 8,000, it got worse and worse.

Steve Taddei: So Dr. Sousa's research suggests that SARS-CoV-2 may affect our auditory system, and specifically more so in the higher frequencies, which are very important for providing speech clarity. In his research, they mainly focused on patients who experienced a more moderate-severe response from the infection. So in these cases, what might be causing that auditory damage?

Francisco Alves de Sousa: If you are considering that this is a true viral impingement or the virus is getting deep into the cochlear structures, like the hair cells, outer hair cells, inner hair cells, it can be that like in moderate to severe patients, you have a bigger viral load, since the disease is worse, right? That's why they are in hospital. And that greater viral load would explain that the infection would extend also to the lower frequencies range, not only the 8,000 or 6,000. Other explanation is that the patients are ill because of a response from our immune system to the virus. And if you have like a bigger response, you would illicit a bigger disease and a bigger cochlear infection, for instance. And the other one is that it could be like a pre-existing tendency for significance.

It is possible that this is like a transient infection, that for some reason, as you get anosmic, right, with COVID-19 and many patients recover, why not you'll have like a transient infection from your cochlear cells? We don't know. I think it's really important to know that, and not to be panicking about the situation, and so don't be afraid or think that only because they get COVID-19, they'll get some kind of profound and irreversible or danger hearing your loss. It's not actually what we see in the clinic. I think it's good that we are motivated to study the effects of this new virus and our system.

Steve Taddei: When we come back from the break, we'll be speaking with Dr. Kevin Monro, who is another researcher looking into how this infection can affect our hearing. We'll also follow up with Antonio, so we can hear the rest of his story and learn what he's done to cope with his hearing loss and overcome any barriers as a result of it.

So far, this episode, we've heard from Antonio about his sudden sensorineural hearing loss. And though it had nothing to do with COVID, it illustrates how a viral infection or strong auto-immune response may affect our hearing mechanism. We then spoke with Dr. Francisco Sousa and learned that his work during the pandemic suggests that SARS-CoV-2 may cause hearing loss in moderate to moderately-severe cases of infection. I wanted to dig further into what the research was saying about COVID. So, I spoke with Dr. Kevin Monro, who is a professor of audiology, Director of the Manchester Center for Audiology and Deafness and Deputy Director of the NIHR Manchester Biomedical Research Center.

Dr. Kevin Monro: Of course a year ago, like most people in the world, I didn't know very much about coronaviruses at all, but then this pandemic struck us. Members of the public started to email me and ask about hearing loss and tinnitus that they were experiencing and that they thought was related to having COVID-19.

And, at that time, what we found was that the other coronaviruses that we knew about, like SARS, that occurred almost 20 years ago, and killed 800 people ... there was no evidence that SARS was causing any ear problems. And then MERS, the Middle East Respiratory Syndrome from 2012. You know there were about ... I think it was 8,000 fatalities. But again, nothing to suggest that was related to ear problems.

But when we did research, we came across seven articles. There were people suggesting that it was affecting their hearing, causing tinnitus, and causing vertigo.

Steve Taddei: In order to learn more about how COVID is affecting people, Kevin and his team worked with the hospital to identify 121 adults who had been admitted due to coronavirus.

Dr. Kevin Monro: As part of the, just a routine follow-up, their physician was asking them lots of questions about fatigue and shortness of breath. And in amongst all the other questions, they asked them if they thought, had there been any changes to the hearing or tinnitus. And what surprised us is out of the 121 adults, more than one in 10, it was about 13% said that something had changed with their hearing.

Steve Taddei: Everything was suggesting a connection between hearing loss and COVID-19. However, Kevin and his team wanted to see a direct comparison between people who had been hospitalized due to COVID and people who had been hospitalized for other reasons.

Dr. Kevin Monro: We've been able to secure, fantastically, research funding to carry out our own study. And what we're going to be doing is we have a bespoke mobile hearing research van that has all the facilities we need. So we'll be able to drive to the homes of individuals. And our plan is to recruit, about 100 people who were in the hospital with COVID. And we'll test them. And then we'll also test and compare them to 100 people who are in hospital, but didn't have COVID. So these might, for example, be people who still had shortness of breath because they had what you might call bulk standard pneumonia, but it wasn't the SARS-CoV-2. And, we're going to compare them. And that's what we will do over the course of this year.

We're really trying to understand, why are they reporting these problems? Is it because the virus has indeed damaged their auditory pathway somewhere, either the cochlear or the nerve. Is it that their hearing's being damaged indirectly because of an abnormally strong immune response, a cytokine storm, the body fighting the virus. Other things that just happen to you when in hospital because of lack of oxygen or ototoxic medications that they might have had that could damage their hearing or, you know, just people who had in critical care have all sorts of health problems.

And, it's also just possible that, you know, for some people, maybe they had a preexisting hearing loss, but it's now everyone's wearing face masks. You're taken to hospital. You're anxious. You're in a noisy environment with ventilators. People are talking to you using terminology you've not had before.

Steve Taddei: Kevin's research will help estimate how common auditory disorders are for people who contract COVID. Furthermore, it will help answer the question, is coronavirus damaging our auditory system? If so, what is that damage, and what can we do about it? Though all signs are suggesting that COVID can cause auditory damage, Dr. Kevin said we should remain cautious of how we interpret the data that's available.

Dr. Kevin Monro: Our review of the literature seems to suggest that round about 10% of people are reporting these problems. But there's not been these kind of definitive high-quality studies, so we just have to be a bit cautious that we don't say 1 in 10 with COVID are getting these problems. And in a year or two's time, people might look back and say that was complete rubbish. So that's the way it's looking right now, but we have to be cautious until we've done these other studies to be sure about these numbers. So I would just be cautious about that.

Steve Taddei: So what if you have a sudden hearing loss as a result of COVID or some unknown reason. Firstly see a medical healthcare provider immediately. Get your hearing checked, so you know what's causing the change and how to treat it properly. While it may be something as simple as ear wax, it could be something more severe requiring immediate treatment. And as we discussed earlier, treatment for sudden hearing losses needs to occur as soon as possible.

If you do end up with a permanent hearing loss, remember that there are amazing technologies and therapies available. There's almost always something that can be done. Hearing aids are extremely advanced pieces of technology that provide a prescribed amount of volume to compensate for your hearing injury. Even if your hearing loss is beyond what a hearing aid can help with, there are specialized devices that can route sound from your bad ear to your better one.

In Antonio's case, he has learned great coping skills and has used a hearing instrument to aid his worse ear.

Antonio: When talking to clients or talking to my coworkers, if they're standing on my right side of my ear and they talk at a normal volume for them, or a little bit quieter, I can't hear them. Like I will not be able to pick up anything that they say. But over the time I've grown to kind of audibly listened through my left ear to try to catch what something on my right ear would catch. So there's at times where I can maybe catch a snippet of something and I'll look at them and like know that they said something.

I did have a hearing aid and it was very, it was actually helpful because even though I have no hearing in my right ear, I can still, at certain volume, hear stuff. So for example, if I go to a concert, I'm going to not be able to hear it as clear, but in my right ear its still accepting it, and I can actually kind of hear.

Steve Taddei: If we reflect over the past year, it's easy to dwell on how our lives have changed. But with each day, we learn more about COVID and how to fight it. We see regular progress amidst the pandemic, and now with the rollout of vaccines, a return to normalcy feels almost in reach. New research, like the studies performed by Dr. Francisco Sousa and Dr. Kevin Monro will give us even more of a fighting edge on how the virus may affect our hearing mechanisms, and then what we can do about it. So while there's more to be done, the end is in sight and we can get through this together.

The Hearing Tracker Podcast is hosted by me, Steve Taddei. Each episode, we reach out to people with hearing difficulty and / or industry leaders to talk about the hearing system, innovative technologies, and what's to come. This episode was written, produced, and sound designed by me with help from Abram Bailey and TJ Belek.

We'd like to thank Antonio for sharing his story with us and all of you out there listening. We'd also like to thank Dr. Francisco Sousa and Dr. Kevin Monro for their tireless efforts throughout the pandemic. We look forward to seeing more of their work in the future.

If you have a unique story related to your hearing, or if there's another show topic you'd love to hear, share it with us and send a line to steve@hearingtracker.com.

Finally. You can find much more helpful content and keep up to date by visiting us on Facebook, Twitter, or HearingTracker.com. Thanks for listening.