How the Neosensory Duo Could Reduce Tinnitus – David Eagleman, PhD

How the Neosensory Duo Could Reduce Tinnitus

Ben Thompson, AuD.

Hello and welcome. This is episode number 19 with the Pure Tinnitus & Hearing Podcast. My name is Dr. Thompson. Today’s special guest is David Eagleman, Ph.D., neuroscientist, author, technologist, and entrepreneur. Dr. Eagleman’s research encompasses brain plasticity, sensory substitution, time perception. And we’re here today to talk about his work with the company called Neosensory. They’ve recently released a product, a technology called the Neosensory Duo, which is a wristband. And we’re here today to meet with Dr. Eagleman and learn more about how the Neosensory Duo could potentially help people with their tinnitus. Dr. Eagleman welcome. And let’s start with learning a little bit about your history with the company Neosensory, and how your company got involved with tinnitus.

Dr. Ben Thompson and Neuroscientist David Eagleman discussed how the Neosensory device could possibly help people with tinnitus.

David Eagleman, PhD.

Yeah, great. So I’ve run research labs since I was a young man and I got really interested in this issue of sensory substitution, which is how can you feed information into the brain via unusual pathways. And so one of the things that I got interested in my lab is could we address deafness where, so, you know, there are about 220 reasons why somebody might go deaf, could we push auditory information into the brain via another channel. And so what we came up with at the time was a vest with vibratory motors all over it. And it would capture sound and turn sound into patterns of vibration on the skin and people who were deaf could come to hear the word that way, like actually hear the word, which sounds crazy of course, but it’s because the ear is just transferring air compression waves in despite that go off to the auditory cortex, we were able to just get spikes to the brain via another channel. So we built this device which is called the Neosensory Buzz when we reduced the vest down to the wristband and this has vibratory motors all along here. Okay, so that’s how the company started. I spun that off from my lab about six years ago now.

But more recently, what happened is we were just studying the literature and looking at what was going on. And we saw that there were two different groups who were addressing tinnitus in particular. One was a Susan Shore’s group from University of Michigan. And one was Conlin at all this group from Ireland that was addressing these in scientific papers. And what they showed is that candidates could be driven down the aversiveness of tinnitus could be driven down by what’s called bimodal stimulation, which is having sounds played and simultaneously having touch going to the body. Now, both groups used shocks on the tongue and they used an electro-tactile grid on the tongue. And what they found in these published papers was that the combination of these obviously it’s called bimodal ’cause it’s two modes it’s hearing and it’s touch. They found that it drove the aversiveness of tinnitus down. And so I was really intrigued by these studies and I thought, wow, I wonder why they use the tongue. And it turns out the reason they did that is because Susan Shore’s lab was studying a very particular nucleus called the dorsal cochlear nucleus, which is involved in that’s the first place where auditory information meets, touch some of sensory information from the head and neck. And that’s why they use the tongue because they wanted head and neck stimulation to meet the thing. Now why the dorsal cochlear nucleus? It’s because that happens to be what they were studying separately in animals. They happen to dunk their electrodes in the DCN. And so they were doing studies to see if they could match it up. But the thing that struck me as almost all the time in neuroscience, whenever somebody says, hey, I think this is the spot in the brain where something is happening. It’s usually not the case. It’s usually just because that happens to be where they’re, it’s the drunk looking for the keys under the streetlight. So anyway, I thought let’s try this. Let’s try and see if bimodal stimulation with stimulation on the skin from the wrist does the same thing. And so we’ve been studying that for a while now and we get exactly the same results that Susan Chore’s lab did and the Irish Group did. The Irish Group has spun off a company called Linea, which does sound plus electro-tactile shock on the tongue. So that’s how we got here.

So we tried this just to see if this bi-modal stimulation would work if it’s on the skin, it works just fine. I’ll tell you my interpretation of this. I mean, there’s detailed interpretations, but the simplest way to look at this is that there’s brain plasticity, your brain is constantly changing and reconfiguring, and so on. And I think what’s going on here might be as simple as this is teaching the brain the difference between external and internal sounds. So when you are hearing a sound and feeling verification of that sound on your skin, your brain says, oh, okay, got it. There’s a sound in the outside world and I can tell that’s an external sound because I’m hearing it and I’m feeling it. In contrast when there’s tinnitus happening. You’re not feeling anything here. And so your brain says, oh, I get it. That’s an internal sound, that’s different. And so what happens is, you start seeing the results from that. And with the Linea Group, the Irish Group, they do their thing usually for 10 to 12 weeks, we’ve done studies where we do this for eight weeks and we find about the biggest result. Although we found it in a few people that it keeps going a little bit to 12 weeks, but yeah, so it’s not an instant thing. It takes a little bit for your brain to reorganize to drive that down. And by the way, when I’m talking about driving it down, I want to specify two things which is, it’s not a cure for tinnitus, but it drives down the aversiveness as measured by the tinnitus functional index, the TFI, which probably many listeners are familiar with, asked a series of questions about how it’s affected their lives, how they feel about it, this sort of thing and those scores, the scores go down a clinically significant amount. So on the TFI, it’s considered clinically significant, a few drop by 13 points. And most of our subjects have that or bigger.

Ben Thompson, AuD.

Okay, well, we’re going to get into that science in a little bit, really excited about that. And Dr. Eagleman thank you so much. We’re so glad you’re here because anytime a neuroscientists like yourself and a research group chooses to research tinnitus more, we know that we’re getting closer to understanding the complexity of this is much more than just an ear phenomenon here. So other systems in the brain that are very much involved in this sustained activation of tinnitus, and you’re an author, you’ve written eight books, you are a brain lover, you’re fixated on the brain. You’ve done great work with that. Your latest book is called “Live Wired.” You talked a bit there about showing the brain that tinnitus is an internal signal. And having that validation through that bi-modal stimulation. Tell us the difference between someone who can hear what you’re saying, understand it cognitively versus the brain being shown it and knowing it at a subconscious level and how there’s differences between those two levels of understanding and one might affect the actual level of tinnitus whereas the other might not necessarily.

David Eagleman, PhD.

Yeah, I mean, almost everything that brain does happens at an unconscious level. So what we are conscious of is just the tiniest little bit, the conscious mind is like the broom closet in the mansion of the brain. So this happens all the time. I mean, if I were to tell you as a kid, okay, here’s how you ride a bicycle, you bounced a tour. So you, you know, I can tell you all that, but you need to actually do it and train your brain unconsciously on that. Likewise, if I say to you, you know, hey, don’t worry about the tinnitus. It’s just an internal sound. It’s not actually a real sound in the world that the cognitive influence on that is essentially zero. You need to actually train the brain to understand the difference between external and internal sounds yeah.

Ben Thompson, AuD.

That’s really huge, that’s really huge. So overall, how does the wristband work? If you, if someone asks you really quickly, how does this wristband work? What is your response?

David Eagleman, PhD.

Yeah, so capture sound and it translates that sound into a spectrum of frequencies on the wrist. If I play a high sound beep, it’s shown up over here. If I play this and it looks on boom, it comes out over here. The way this works for people who have hearing loss is that you’re capturing the whole world and doing this the way we’re doing this with tinnitus. It’s the same hardware exactly but what we’re doing tinnitus is we play a series of tones. We’ve been trying all kinds of experiments about, so our, I should say our first set of experiments, it’s just tones going up and down and up and down. And the band is responding to these, but we’re doing other things now where we’re playing unpredicted tones with different durations, all of it’s unpredictable. This is just a minor tweak because the brain responds best to things that doesn’t quite predict. So that’s one of the things we’re offering now, but what a lot of a lot of people do now is they just wear the surround while they’re walking around during the day.

So in other words, they play the tones, which is the training. And what we found in our experiments is that 10 minutes a day is sufficient. So, you know, you just do something quiet. You read a book, you surf your phone on, whatever. But for 10 minutes, the brain is really getting these tones. But what a lot of people do is they then wear it around outside of that also, so that they’re picking up on the sounds of the world. So in the microwave beeps or the door shuts or whatever, they’re just hearing sound and getting verification of it. And that seems to be great as well.

Ben Thompson, AuD.

That’s fantastic. And of course, whenever there’s a new technology in the tennis world, we are optimistic and simultaneously patient trying to get as much data and objective information on this as we can before making any big promises. As you’ve said, this is not intended to cure tinnitus. None of the bimodal stimulation devices are. I want to ask you a user question. I asked the Pure Tinnitus community that we are having this interview, and there was a user question about, would it be more beneficial to use the Neosensory Duo wristband for longer than 10 minutes a day? And why did your research group decide to go with 10 minutes as a standard daily practice with it?

David Eagleman, PhD.

Yes, so we ended up doing, you know, so as I said, we looking at the papers of what had come before we realized that it doesn’t have to be that long. And by the way, 10 minutes of sitting and listening to tones is a long time and enough. If you imagine spending 10 minutes, trying to learn how to ride a bike every day, you get pretty far that way. So that’s what we ended up running for the studies. And what we found is that, that work that drove the diversity of tinnitus down as measured by the tinnitus functional index. And so that’s why we did it.

Now a lot of people have written us to say, hey, I’m using it for longer. I’m using it for half an hour a day. I’m using multiple sessions a day and that’s great. We don’t actually know at the moment, whether there’s a significant difference there, whether that makes it better or not, but it certainly doesn’t hurt. So we are telling people great, as long as you did at least 10 minutes, that’s what you need. And if you use it for longer, that’s great. I think as we get more data in over the, you know, over the coming years, we’ll start seeing whether the people who wear it for a lot longer, have a really different clinically different out, significantly different outcome.

Ben Thompson, AuD.

Thank you so much. And I want to bring this into another important point here is that a lot of tinnitus sufferers or people who are really suffering with tinnitus are in a state of high anxiety and insomnia. And with your knowledge of the brain and how these systems work with each other. First of all, it’s important to know that people have reduced their tinnitus without these technologies we’re talking about, although they are the newest most promising research developments, other people have reduced their tinnitus without them because being a tinnitus telehealth specialist myself, people are often asking me in a very anxious state. Do I need to do this right now? Am I missing out? And I just wanted you to comment from your perspective knowledge of the brain, about how anxiety, insomnia, stress might influence tinnitus and how the Neosensory Duo or any treatment product technology plays a role in that.

David Eagleman, PhD.

Yeah. It seems a big part of the problem with tinnitus of course, is the emotional reaction to the sound. And so, just as an example, what we were mentioning before about if the brain understands it as an internal sound, that it doesn’t need to pay attention to, that makes a big difference. But I think there are probably lots of different angles on reducing stress. And so obviously when people meditate, when they get better sleep, when they stop drinking, which disrupts her sleep. So there’s all kinds of ways of reducing stress, such that when people hear the sound, they don’t have to feel anxious about it. So what we of course are recommending to people is to try all of this in other words. So just as an example, for people who pick up the Neosensory Duo, we tell them terrific, do this. And by the way, here are other tips on reducing stress in your life as well. My, I mean, I think we probably share the suspicion that there’s the best way to do this is to hit all those fronts to make sure you’re getting good sleep, good diet, reducing stress in your life.

By the way, I noticed something amazing. I didn’t have a chance to tell you about this has been but so we’ve been measuring the tinnitus functional index on a whole bunch of participants going through this and back in, I think it was March if I’m remembering this correctly when we changed daylight savings time and suddenly everyone lost an hour of sleep. Everyone’s tinnitus bumped up that week, just be, but anyway, it was a real illustration to me of how just a little something like everybody losing an hour of sleep, really drove it up just temporarily. So anyway, it’s so clearly related to all kinds of issues about how your body is doing that, that day or that week.

Ben Thompson, AuD.

Yeah, we call it tinnitus, the health amateur, or the barometric pressure reader of the body. And the most common reason someone has a sudden onset in this is to studied in 1995 by the Hazel Group within this et cetera. The two most common factors associated with the emergence of sudden onset bothersome tinnitus were stressors around work or retirement or money or interpersonal relationships or anxiety or stress around that. So those are not auditory, only fourth on the list was acoustic trauma. So it shows us that yes, it’s related to the ear, but usually, the driver for sudden onset loud tinnitus is not the auditory pathway individually. So really fascinating stuff and I want to transition into some nitty-gritty scientific questions. It won’t be textbook, boring, scientific questions. These will be fun, exciting questions that people do like to learn about because it gives them more knowledge of what’s happening with their tinnitus. And if you’re a professional listening or watching, this will help you counsel patients because you’re going to get a lot of questions about the neosensory duo and other bimodal stimulation devices in the next few years I believe.

So question number one, what regions of the brain need to change for tinnitus to reduce in loudness, which can happen. And I’ve seen it that does happen. What needs to change in the brain for tinnitus to reduce in perceived loudness or perceived annoyance.

David Eagleman, PhD.

Yeah, these are terrific questions. And we don’t actually know the answer to, we as a community writ large don’t know the answer. What seems to be the case is that the limbic system, which is this deep emotional center, seems to be very involved in what happens with one’s reaction to tinnitus. So for most people with tinnitus, it ends up being really stressful and anxiety producing. And what the general story seems to be with any of the approaches, whether it’s bimodal stimulation or meditation or better sleep or whatever is unhooking it from the limbic system a bit. So that it doesn’t feel so stressful. And this is in part what the TFI is measuring. It’s not simply the loudness of it, but the avers