Hearing Loss Therapies Backed By Science
Search Google for "Hearing Loss Cures" and you'll be inundated with pseudoscientific cures and other quackery. While there is currently no magic pill to cure your hearing problems, there are some legitimate science-backed hearing therapies that have begun to emerge over the past few years. In today's episode, we talk to leading pharmaceutical and digital hearing therapy providers to learn about the current and future prospects for improving your hearing without hearing aids.
Podcast transcript
Ad announcer: Support for the Hearing Tracker Podcast comes from Nuheara. Nuheara is transforming the way people hear by creating personalized hearing solutions that are multifunctional, accessible, and affordable.
Steve: Hearing loss affects nearly 40 million American adults. Worldwide there are over 400 million people dealing with a disabling hearing loss. And these numbers are projected to rise in the coming years. With such staggering numbers. You may find yourself asking why isn't there a cure for hearing loss: "Why is it that hearing aids remain the main method of treating hearing difficulty?"
In this episode, we'll explore cutting edge pharmaceuticals and aural rehabilitation therapies that may change this landscape. And the future of hearing loss possibly forever. After this episode, you may just find yourself asking another question: "In the near future will hearing loss become a thing of the past."
It's happened to us all. You wake up, feel a tickle in your throat, a soreness as you lean over, and those horrible chills. You try to deny it, but you are sick. Before you know it, you're calling off work and heading to the store for some medicine to get you through the next 24 hours.
Medicine and pharmaceuticals have been around for decades. In fact, some studies have found evidence of them 60,000 years ago. Present day, we have medicine for nearly everything, but one area that we have yet to see a breakthrough is for hearing loss.
Can you imagine a world where you take a pill in your hearing is better by morning? Believe it or not, there is one company that's trying to make this a reality.
Carl LeBel: We're taking a regenerative medicine approach. We're acting on cells that are already in the cochlea.
Steve: That's Dr. Carl LeBel, the Chief Development Officer at Frequency Therapeutics. They're a company that is in phase two clinical trials of a hearing loss treatment called FX 322.
Carl LeBel: What we're doing is we're delivering two drugs. One of those drugs is valproic acid. It's a common anti-epilepsy drug or for migraines as well. And then the other drug is what's called a GSK-3 inhibitor, it's glycogen synthase kinase. What we believe the drugs do is they act on progenitor cells that are in the cochlea.
The way that it's thought to work is on sort of epigenetics. It opens up targets or opens up genes or gets genes kind of ready to be turned on.
Steve: You can think of progenitor cells as pre-programmed stem cells. And they can be found throughout the body, but also within the cochlea of our hearing system. If you don't know, the cochlea is a cavity within our skulls that houses receptor cells.
You've probably heard them called hair cells. These hair cells have a very important job. They're responsible for converting sound vibrations into an electrical impulse that our brains can process. For millions of people around the world, these cells have become damaged and that's what's causing their hearing loss.
It's not uncommon in science for new discoveries like this to come from a lot of hard work with just a little help from luck. These two drugs, valproic acid and the GSK-3 inhibitor, and their possible application for hearing originally had nothing to do with our ears.
Carl LeBel: Some of our co-founders were looking at the small intestine, which is a highly regenerative tissue, and it was striking to them how regenerative it was. Along the lines of every four days, the lining of our small intestine completely turns over and they identified some cells called LGR5 cells. And those are the cells that are really responsible for the signals and making this regenerative process happen.
They were groups that identified in the cochlea. There are similar progenitor cells, these LGR5 cells. The difference is in the cochlea, they don't do anything. And they're actually turned off. They're inactive. They provide support ... sort of structural support and communications and so forth. But they're inactive.
Steve: Progenitor cells in our cochlea weren't always inactive. As it turns out, they develop in our first trimester and they have one major job ... making sensory hair cells. This is why we're able to sense sound around 18 weeks of pregnancy. Unfortunately, when we're born, they turn off.
Carl LeBel: And the discovery here, that's sort of identified in the small intestine and then eventually translated to the cochlea... What we've been able to do now is by giving them our two drugs is we wake them up and we remind them of what they were there for. They divide, and then they form a new hair cell. Our work in the labs suggests that the end result of that is an improvement in hearing.
Steve: Frequency Therapeutics, and their drug FX 322, ultimately calls on our body's innate ability to repair itself. So what is it like to receive this drug FX 322?
Carl LeBel: The way that we deliver FX 322 is via an inter tympanic injection. So this is an injection that is done with a, usually a small gauge needle through the eardrum. It's done under anesthesia. So our otolaryngologist or ear nose and throat physicians, what they do is they apply a little bit of anesthetic to the ear drum, and that numbs the ear drum, and then they advance the needle through the eardrum. It's a relatively painless procedure. There's some mild discomfort that's associated with it. And then FX 322 is injected into the middle ear space now. So we've gone through the eardrum and injected into the middle ear.
Steve: Once the FX 322 solution is injected, something very interesting happens. FX 322 is what's called a thermosensitive solution. This means it's a liquid at room temperature, but when exposed to the warm environment in our middle ears, it transitions quickly into a gel. And this is a very important stage in getting FX 322 into the cochlea or our inner ears.
Carl LeBel: And so there's a structure called the round window membrane. It's kind of the screen door between the middle ear and the inner ear and those small molecule drugs that are sitting in that gel now can diffuse through that round window membrane into the cochlea and distribute themselves and start looking for those progenitor cells.
Steve: I mentioned earlier that Frequency Therapeutics is in phase 2 of their clinical trials. So what are realistic expectations? And what benefits are people actually seeing?
Carl LeBel: The excitement that we have and that the field has, is you know, we've been doing these two measures of speech intelligibility. So we do the words and noise test and several of the subjects, the more moderately-affected subjects, when they were dosed with one injection of FX 322, in several cases, there were, there was a doubling in their word scores, which is, which is quite remarkable. And remember these patients have stable hearing loss for quite some time. So to show those kinds of improvements was really exciting.
Steve: Speech intelligibility tests are very important and can provide great information regarding a person's hearing. For example, one person may accurately repeat 50% of the words presented. Someone else with an identical hearing loss may accurately repeat 96-100% of the same words. Now these numbers do not indicate the percent hearing loss. Rather they reveal the fidelity of your hearing system in the absence of visual and context clues. This information can be a very strong predictor of how well you'll hear in various environments and with different hearing devices. So a doubling of speech intelligibility, as seen with some of their participants, can have a profound effect on your quality of life.
Another common measure of our hearing is thresholds. This refers to the softest possible sounds we can hear. Let me give you an example.
That was a 1000 Hz tone, a frequency commonly tested. If I gradually decrease that tone, at some point it will fall outside of your hearing range.
The level right before it seemed to disappear is known as your threshold and a hearing test involves many different tones.
Dr. Carl went on to describe how FX 322 has affected people's hearing thresholds.
Carl LeBel: In the first trial, we noted that subjects that showed improvements ... pretty clear improvements in their word recognition scores... several of them also had 10, almost 15 dB, threshold shifts at 8,000 [Hz]. So we think it's distributed down to about 8,000 [Hz] and then clearly well up into the extended high-frequency range.
We don't see FX 322 eliminating hearing aids. We actually see it... it could potentially be used in combination. You might have a subject that might be a candidate for a cochlear implant, and they could potentially be treated and then moved to being a hearing aid candidate. And then there might be people that use hearing aids that could be treated and maybe they don't need to use hearing aids any longer.
It gives ENTs a tool today that they don't have… So it's not too, too far off. We still have several years to go. But I think that we, we think it gives people hope. And it certainly gives us hope, and we're doing everything we can to speed that process along. You know, we're going to do our best
Steve: Frequency Therapeutics hopes to learn more about FX 322 in the coming trials. They'll also assess the benefits of multiple doses and use a broader set of tests. Hopefully results will continue supporting the many implementations of their drug. When we come back, we'll be speaking with AudioCardio, another interesting company that's developed a digital therapeutic for people with hearing loss.
Ad announcer: Support for the Hearing Tracker Podcast comes from Nuheara. Nuheara is transforming the way people hear by creating personalized hearing solutions that are multifunctional, accessible, and affordable.
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I recently spoke with Chris Ellis, the CEO of AudioCardio. Their company has developed a digital therapeutic, or sound therapy, that helps you exercise your ears.
Chris Ellis: AudioCardio is a mobile app that's designed to help individuals maintain and strengthen their hearing. We wanted to find a form factor that was easy to get to a lot of people.
Steve: The idea for their therapy arose after watching a family member struggle with untreated hearing loss, social isolation, and cognitive issues. After witnessing this, it was clear to Chris and his co-founder. That an easily accessible therapy is needed ... a therapy that helps keep your hearing system engaged, so atrophy doesn't set in and the effects of hearing loss are hopefully minimized.
Chris Ellis: We're using the concept of neuroplasticity or in more particular adaptive plasticity is when you repeatedly do something over and over again. It can become a habit. It's like imagining your brain as billions and billions of dirt roads. The more you use those dirt roads, the easier they are to find, take, and reach your destination. Or in this example, it's completing your function or your goal interpreting a sound.
So what we're doing is consistently stimulating those cells over and over again, until they reach that threshold that causes them to fire. And then when they do, that's how that signal gets into the brain, and then you recognize it as sound. By doing that over and over again, these cells remember those pathways, which makes it easier for them to take. They'll continuously take that pathway.
You would go into a very quiet room away from ambient noises, like refrigerators and theaters and things like that ... cars passing by. Connect your headphones or your ear buds to your tablet or smartphone, and you would take a brief hearing assessment. And that hearing assessment is really a calibration of your sound therapy. We're using those inputs to generate a personalized and inaudible or barely audible sound therapy. It's right at your threshold of sound, where we stimulate the cells. And the process of doing that hearing assessment though is quite simple.
Steve: The hearing assessment is very similar in concept to what you may have done at a hearing clinic. You'll be presented different tones and you'll adjust a volume slider until the tone is just barely audible.
From this calibration AudioCardio will generate your personalized sound therapy, which might sound something like this.
Chris Ellis: For an hour a day is what we recommend. Of course some use is better than none. You can be doing other things while you are receiving the sound therapy. So you could be going for a walk working on your laptop or even exercising, but over time it will get louder and it will become annoying. And it will disrupt whatever it is you're doing. That's also your cue to go ahead and retake your assessment so that you can generate a new, personalized sound therapy for your new ability. And you would keep doing this over and over again to drive down your threshold of sound.
It means your hearing is changing because you're now able to recognize this tone that's being played at that barely audible level is becoming more clear. And so we want to keep going, just at it or just below to help stimulate the cells to get used to receiving that frequency in transmitting it to the brain.
Steve: This is an important thing to note about AudioCardio. It's meant to be listened to passively, so it should barely be noticeable if your initial assessment was done properly. AudioCardio wanted to test the effectiveness of their therapy and they conducted a study through Stanford University.
Chris Ellis: We have done some clinical studies, including a double-blind randomized controlled study with Stanford University in Palo Alto Medical Foundation. Over 75% of the participants in that study had a change in their hearing by 10 decibels or more within three weeks, for the frequencies that we targeted. So we are seeing a significant shift in threshold by utilizing the AudioCardio solution or the underlying technology, which is called threshold sound conditioning.
Steve: AudioCardio has received high praise from users. It's claimed to have helped those not using any other hearing technologies, long-term hearing aid users, and even those suffering from tinnitus.
Chris Ellis: Tinnitus can often be a symptom of hearing loss. And so for certain individuals who are experiencing tinnitus and have used AudioCardio, not only have they reported back a benefit in terms of their actual hearing levels, but also in the reduction in frequency of their tinnitus.
James: The ringing in the ears that, uh, you know, it kind of, it always reminds you that something in you is broken and that really bugs me.
Steve: That's James, a user of AudioCardio. He has a mild hearing loss, which he's been able to cope with well. However, he struggled with tinnitus for years.
James: Nothing too crazy. Like I can still hear through the ear, but it's just this static.
Steve: James had tried to manage his tinnitus in the past, but it was often triggered by commonplace sounds such as his kitchen fan, road noises, and even slight changes in air pressure. He eventually came across AudioCardio.
James: I figured, you know what? Like it has a two week trial. So it was like, okay, I'll give it a shot. The biggest thing I noticed overall, just day-to-day life was that when I would be using it, that tinnitus, it just, it didn't go away, but it lost a lot of it's um, aggressiveness. It kind of just shaved off the pointy ends of the tinnitus, which really kind of helped smooth it all over. And all of a sudden it didn't really bug me anymore. Even though I could look for it and be like, oh, there it is. It didn't bug me anymore, but it wasn't as sharp.
The positive effects that AudioCardio's had ... and I don't think it's a placebo effect at all, because I can hear in the higher frequencies, I can hear a little bit better, and it definitely does calm my tinnitus. And none of the other little tricks and gimmicks I tried before it did anything. It's, it's just insane. Like it does ... I think it really did help me.
Steve: AudioCardio will continue developing their software and they look to conduct more research to better understand the benefits of their app. They hope it can become a complimentary solution along with other aural rehabilitations, technologies, and of course, hearing conservation.
This month's episode explored a few innovative companies pushing the boundaries in pharmaceuticals and therapeutics, but there is much more going on. Be sure to subscribe to our podcast and visit HearingTracker.com for the many updates and resources available. This episode was written, produced, and sound designed by me with help from Abram Bailey and TJ Belek.
We'd like to thank Frequency Therapeutics for speaking with us about FX 322. To learn more about them, you can visit frequencytx.com. Over the next year, they will be conducting more research. So if you're interested in participating, go to clinicaltrials.gov to check your candidacy and see if there's a participating clinic in your area.
We'd also like to thank Chris, AudioCardio, and James, for speaking to us about their technology and experiences with the app. To learn more, you can visit them at audiocardio.com or download their app in the app store.
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.
- pharma
- hearing loss