The Crucial Link Between Cognition, Audition, and Amplification

Ever wonder how cognition, audition, and amplification are all interconnected? Discover the fascinating connection in this week's Hearing Matters episode, where we also explore the challenges of diagnosing auditory processing disorders with no hearing loss on an audiogram. Learn about the groundbreaking research of Dr. Anu Sharma and Dr. Hannah Glick, and how cross-modal recruitment plays crucial role in cognition, audition, and amplification.

Neuroplasticity and its relation to auditory processing disorders in children and age-related hearing loss in older adults are discussed in this enlightening conversation. Find out about the common cause hypothesis, which links age-related hearing loss and cognitive decline, and the importance of effective management of auditory processing disorders. We also delve into hearing technology such as FM systems, hearing aids, and pocket talkers that can improve signal-to-noise ratio and help the brain focus on what to pay attention to.

Before you consider any solutions for auditory processing disorders, it's crucial to get a proper diagnosis from an audiologist or licensed hearing healthcare professional. We discuss the significance of low gain hearing technology, and highlight the National Council on Aging 1999 study, which emphasized the benefits of correcting hearing loss. Providing auditory access to the acoustic world can help individuals thrive - don't miss out on this insightful episode as we unravel the mysteries of cognition, audition, and amplification.

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Transcript

Dr. Douglas L. Beck: 0:00

Well, the connection between all three is the human brain And when you think about cognition or dementia, mild cognitive impairment, when you think about cognitive decline, these are all things that intertwine and interconnect with auditory processing, with language, with cognition. All of these things are interdependent on each other Dr and Michael Bust in 1949, just about when audiology was being formed was talking about. You can't really separate cognition from audition, from language. They're all pretty much intertwined sciences And if you try to just separate out audition you very quickly run into problems because you could have somebody who doesn't understand speech and noise, as we were talking about last week. That might have an auditory issue, they might have auditory processing disorders. But many people will have no hearing loss whatsoever and they will have auditory processing problems. They might have auditory neuropathy spectrum disorder. They might have cochlear synaptopathy. They might have hidden hearing loss. They might have ADD, adhd, dyslexia. They may have neurocognitive problems.

Blaise M. Delfino, M.S. - HIS: 1:09

You're tuned in to the Hearing Matters podcast, a show that discusses hearing technology best practices and a growing national epidemic hearing loss. Before we kick this episode off, a special thank you to our partners Cycle, built for the entire hearing care practice. Weave, the all-in-one patient communication and engagement platform. Redux Faster, drier, smarter, verified Fader plugs The world's first custom adjustable ear plug. Welcome back to another Hearing Matters podcast episode and hoping everyone had a wonderful week. We will be discussing cognition, audition and amplification. Dr Beck, welcome back to the Hearing Matters podcast, thank you Blaze.

Dr. Douglas L. Beck: 2:02

It's a pleasure to be here.

Blaise M. Delfino, M.S. - HIS: 2:03

It is so, so awesome to have you back on the show for lack of a better term, dr Beck. Cognition, audition and amplification. What is the connection between all three.

Dr. Douglas L. Beck: 2:13

Well, the connection between all three is the human brain. And when you think about cognition or dementia, mild cognitive impairment, when you think about cognitive decline, these are all things that intertwine and interconnect with auditory processing, with language, with cognition. All of these things are interdependent on each other Dr and Michael Bust in 1949, just about when audiology was being formed was talking about. You can't really separate cognition from audition, from language. They're all pretty much intertwined sciences. If you try to just separate out audition, you very quickly run into problems because you could have somebody who doesn't understand speech and noise, as we were talking about last week. That might have an auditory issue, they might have auditory processing disorders. But many people will have no hearing loss whatsoever and they will have auditory processing problems. They might have auditory neuropathy spectrum disorder, they might have cochlear synaptopathy, they might have hidden hearing loss, they might have ADD, adhd, dyslexia, they may have neurocognitive problems And the number one thing that they're going to tell an audiologist or a dispenser or an ENT is they can't understand speech and noise. And so what happens is we all look for that audiogram that might be consistent with that complaint. Well, that makes good sense, because if they have audiometric hearing loss, then that would explain some of their auditory processing because they're not perceiving the sounds as well as they might. But then there's 26 million other Americans Right here in the USA, 26 million who have no hearing loss whatsoever on an audiogram but they can't understand speech and noise or they have hearing difficulties. So this is what Harvey Dillon and what I also call suprathreshold listening disorders. Now, the word suprathra means above threshold. When you think about, most of the audiometric tests people are familiar with are the very most basic ones. They press the button when you hear the beep and what we're trying to do there is establish the threshold, that is, the 50% point where they can hear or not hear, in other words, the very, very quietest sounds they can perceive. Well, that's interesting and that's very useful diagnostically, because when we look at threshold tests we can see otolaryngologic abnormalities. We can see otosclerosis in an audiogram. We can see Meniere's disease in an audiogram. We can see a noise induced hearing loss. We can see a fluctuating low frequency loss that might be consistent with Meniere's disease. So that's why we do audiograms, because they line up really, really well with otolaryngologic disease. But even if you have no hearing loss on an audiogram. That doesn't mean that you're free and clear and that there's nothing wrong. There's 26 million Americans who have suprathreshold listening disorders and in my mind, auditory processing disorders is one of those many subsets. But it could be traumatic brain injury, could be dyslexia, could be Alzheimer's disease, could be a million things that have impacted a patient's ability to understand speech and noise but have not impacted their hearing thresholds.

Blaise M. Delfino, M.S. - HIS: 5:00

Dr Beck, you interviewed Dr Anu Sharma and this was an interview that was released in February of 2020 discussing cross modal recruitment. Can you share with our listeners exactly what Dr Sharma was researching, what she found and how her findings relate to cognition, audition and amplification? because Dr Del Fino here at Audiology Services. He will also work with patients who present with normal hearing but difficulty understanding speech and noise, but these findings that Dr Sharma released incredible stuff.

Dr. Douglas L. Beck: 5:34

Incredible stuff. So a couple of references. First, the stuff that Dr Anu Sharma published is in conjunction with Dr Hannah Glick, so I always like to make sure Hannah gets credit too. Their original publication was in Frontiers of Neuroscience, which came out in February 2020. Now, as a friend of both of them, i knew ahead of time that publication was coming out, so I got a preprint. So that's how come in February 2020, we also published the interview in Hearing Review, so they kind of came out at the same time. We give them about a 30 day head start and then we publish the interview. The thing that was so amazing is they studied cross modal neuroplastic changes. So what that means. If I have a full complement of hearing, like a normal healthy person with a normal healthy brain, so my brain is getting the full complement of sounds that humans can perceive, which is 20 hertz to 20,000 hertz Easy peasy. But as I get older and older, or as I have more and more negative events happen in my life, i lose hearing. That's called age-related hearing loss. It occurs because we live in an industrial society. Right off the bat, people will say, oh, you have a hearing loss. That's normal for your age. No, there's no such thing. That is totally bogus thinking. Here's the thing In the USA we have 325 million people. We have 37 to 38 million people who have hearing loss on an audiogram. So the vast majority of Americans don't have hearing loss. It's not normal. When you have it, it could be highly detrimental, because one of the most obvious things is it leads to social isolation. People who can't hear well, who can't participate in conversations, tend to self-isolate. They don't go and mix with their peers, colleagues, friends and family, so they stay home And that's very, very bad for your brain because you're not building up cognitive reserve. Now this podcast can go on for about six hours now, because we're talking about the really important stuff, and what happens is, when we lose hearing, that part of the brain that normally would perceive those sounds, because that hearing is perceiving sound, listening is making sense of sound. So hearing is perceived in a part of the brain called the superior temporal lobe. The scientists listening to this will know it is Broadman's area 41 to 42. The audiologists may know it as Heschel's gyrus. All of those are the same, and so that part of the brain should be stimulated. But as you have age-related hearing loss, as you have acoustic trauma, as you have noise-induced hearing loss, as you have hearing loss from biological processes or ototoxic drugs, things like that. You don't generally hear the high frequencies very well, so that part of the brain is no longer stimulated. Well, funny thing about brains they are incredibly plastic. They change all the time. So if that part of the brain is not being stimulated by sound that it no longer perceives, another part of the brain may grab it. Now, typically we think of the occipital lobe, which is in the back of your brain. That's where vision is processed And your occipital lobe could be really aggressive and say hey, there's a part of the superior temporal lobe not being used, so the occipital lobe may grab it. It could be the sensory motor strip that goes kind of from ear to ear where the homunculus lives, and the homunculus could grab that area to start using it because it's not being used. Brains, like space, have poor vacuum. When you're hearing sound, it's not. 10% of your brain is being used. Your entire brain is being used. Your entire brain is being used. Brand new study. Journal of Neuroscience, march 2021. When we thought the speech was just processed in the temporal lobes, we missed it by a mile. We have clinical evidence through EEG, through functional MRI, through PET scans, that the entire brain is involved in understanding sound. Because you have emotional involvement, you have visual redundancy, you have understanding, you have emotional content in the amygdala. The entire brain is responsible to understand speech and noise, it's not just the superior temporal lobe, and so where we are in 2021 is we're trying to really make sure that we give the brain all the information it needs to make maximal sense out of sound. So with cross modal, what happens is that one part of the brain is taking over for another because the original is not using the anatomy. Dr Sharma and Glick study showed that when you fit patients with hearing aids and what they did was the Oticon Open S1 for six months of daily use, the patient's brain was able to go back to how it started. So, in other words, they reversed the cross modal neuroplasticity And so that becomes remarkably important. Now here's the application of this. I think Dr Delfino and I would both look at a patient with minimal hearing loss who's having no difficulty on speech and noise, no listening or communication disorder problems, and maybe say, ok, well, let's see you back in a year or two and see how you're doing. But now, when we have this study on cross modal neuroplasticity, it kind of cautions us that the patient's brain will negatively respond to a lack of sound. And what Drs Glick and Sharma did was they stimulated those brains and, rather than just waiting to see what happens, the brains went back to functioning normally And they were looking at things like executive function, visual evoked potentials, and that's important because the visual part of the brain got better and better as they lost more hearing And that's great for vision. But it's bad for the brain because we want the brain to be processing sound in the temporal lobe and vision to be processing in the occipital lobe. So what happened was they saw changes. It reflected that the brain was going back to its original presentation mode across multiple centers, including the occipital lobe and the temporal lobes.

Blaise M. Delfino, M.S. - HIS: 11:26

Dr Beck, you report that you don't really believe in administering hearing screenings. Why should audiological evaluations be conducted versus a hearing screening where you just screened 500, 1, 2, and 4,000 Hertz?

Dr. Douglas L. Beck: 11:40

Well, we've been pushing that rock up a hill for about 75 years. We started in World War II saying everybody needs to be screened And of course it's a pure tone screening and of course press the button when you hear the beep or whatever we're going to do, that has been remarkably insensitive to finding people with hearing loss, and the reason for that is it's not generally done in a soundproof booth, it's not done with headphones, it's not done with good instructions, it's a quick on the fly sort of thing and you're gone. When you talk about screening, you're trying to maximize bang for the buck or you're not charging at all. You're just quick screening. Let's see if grandpa has a problem. Well, that's not likely to determine the answer. If you look at the peer reviewed literature from the American Speech Language Hearing Association children who were screened in schools it's about 50% sensitivity. It's not a very good protocol And that's with school nurses and school audiologists doing it, because there's just too many areas where errors can occur. Now there are some screenings that I totally endorse. Number one universal newborn hearing screenings. 99% of all children born in birthing centers and hospitals in the USA and mom and dad probably don't know this, but the kid was screened for hearing loss at birth And we've been doing that for about 25 years now and that's brilliant and that's very important because when we discover children with hearing loss, we need to get amplification to their brain as soon as possible. The ear is a window to the brain and if the child does not have that window open, we're not getting sensory information to the brain. The brain can't develop when it doesn't have information. So universal newborn hearing screenings absolutely brilliant started the University of Colorado and brilliant, brilliant stuff, so I'm so happy about that. I'm also a big fan of cognitive screening. I think this is very important because you have people with suprathreshold listening disorders and it's just as likely to be due to an auditory processing issue as it is to be from a neurocognitive issue, because when you think about the older patients that we mostly take care of, i mean, hearing loss occurs in people at birth. It could be any age, but in general it's older folks that we're taking care of, and when we have somebody 70, 75, 80, 85, 90 and they can't understand speech and noise, well, that could be hearing and it could be listening absolutely. It could also be lots of other things that we mentioned earlier. Just a quick review. It could be mild cognitive impairment, could be neurocognitive disorders, could be dementia, could be traumatic brain injury. that 40 years ago could be from Meniere's disease. It could be from Alzheimer's. It could be from frontotemporal dementia. It could be from cochlear synoptopathy. It could be from hidden hearing loss. It could be from a million things that you don't have hearing loss yet your brain isn't able to process sound. And what's the number one thing we do and this becomes apparent when you think about children Children with APD auditory processing disorders in general have no hearing loss. What they can't do well is take the sounds they're perceiving and apply meaning to it. So what audiologists have been doing for over 50 years is we give them FM systems or we give them hearing aids, or we give them some sort of assistive listening device, perhaps a pocket talker, so their brain understands what to focus on. And there are studies out of Australia that say if you effectively manage auditory processing disorders in children for a couple of years, pretty soon the child no longer needs that tool because their brain, because it's neuroplastic, has learned what to pay attention to. So when a child with auditory processing disorders is treated with an FM system or hearing aids or something like that. That's what they need right now to help their brain improve the signal to noise ratio, to know who to listen to, to know what's important to focus on. So those are very, very beneficial. And we see it at the other end of the scale as well, with older folks, because once you're above 65, you're more likely to have chronic conditions and you're more likely to have hearing loss. Age-related hearing loss and cognitive decline are signs and symptoms that are typical in older folks. So one of the things is we try to figure out well, why do both of these things happen? One of the reasons that's hypothesized is called the common cause hypotheses, which is pretty simple and makes good intuitive sense. Now, i don't want to suggest to anybody listening. This is why they have hearing loss. The neuroscientists are trying to figure this out And one of the most popular hypotheses is the common cause hypotheses, which says age-related hearing loss and cognitive decline happen more often in older people than younger people. Why would that be? Well, one of the common cause things is neurovascular. In other words, you have your carotid arteries on the side of your neck. You have the vertebral basilar arteries going up along your spine. They perfuse your brain. Your brain has arterial blood flow that comes through these vessels. Well, as you age, we develop cholesterol and triglycerides, atherosclerosis, and so a vessel that was originally, let's say, half a centimeter, its exterior stays the same, but the interior gets narrower and narrower and narrower as more and more deposits build up. So the blood pressure eventually increases because your heart is responding to the fact that it has to perfuse the entire body. Well, as those vessels become more and more narrow, blood pressure increases. Now think about that in terms of the labyrinthine artery, which is the artery that feeds your inner ear and your vestibular balance system. Well, if the large vessels are susceptible to all of this occlusion through life, from not exercising, not eating healthy foods, excessive fats, excessive triglycerides, all this stuff So if your carotids can become full of plaque and goo, what do you think happens to the labyrinthine artery? Well, probably pretty much the same. So it could well be although I wouldn't presume this to be true, but it could be theoretically that the lack of blood flow to the brain and the inner ear could be why cognitive decline and hearing loss occur in older people. Do we know that to be true? No, we absolutely don't. I don't want to suggest that it's true, But these are the things that we're trying to work out as neuroscientists to figure out why did these things happen to older people, and that's one of the most prominent theories, and there are three or four others that I've written in a peer-reviewed paper that's in the Journal of Votolaryngology, and do research. Anybody who wants that can go to DouglasLBECcom. We'll find it there. I think it was published in 2020.

Blaise M. Delfino, M.S. - HIS: 17:08

Dr Del Fino, dr Beck just shared so many great golden nuggets there, truly for lack of a better term And you've been specializing in working with patients who present with central auditory processing for well over 20 years, and here at Audiology Services you'll see patients on a weekly basis, test them for central auditory processing And, of course, the recommendation is low gain hearing technology. What has your experience been with fitting these patients with this low gain hearing technology And what have you found throughout the years working with patients who do present with central auditory processing?

Dr. Gregory Delfino: 17:44

The population is unique. It is much as off time. The parents will come and they will retell the story that their child has been tested, there is no hearing loss. They're in a quandary as to what's going on. So after I've gone through the complete peripheral auditory evaluation and gone into the auditory processing, we sit down and we look at the specific areas of concern And then we start to talk about some therapies or some interventions And clearly what I have found that works really well is some of this low level amplification. We always approach the parent and the child with it on a trial basis because I believe it's got to come from them. Their decision has to be whether or not this is going to work for them. They need to take it in the environment in which they're working to see whether or not it in fact impacts the way in which they're functioning. The results we've seen are incredibly significant in that both parents, children and off times learning support at the school have noticed a significant improvement in the way in which the child is able to function. We've seen children here whose self-esteem has completely changed. when we first sit down with them They're shy. They don't want to share their experience, but after they've had the instruments on for a while, they become verbose. It's a whole different child, and that just tells me we are moving in the right direction.

Dr. Douglas L. Beck: 18:52

And this is the essence of patient-centered care. Right Is that you have to take each individual and you can't have. This is what we do for these people. This is how we handle it. Each patient is individual and that's why it's so important when you go through auditory processing disorders and you do an appropriate intervention, You have to explore their listening and communication ability, because there was a study National Council of Aging 1999. They looked at about 2,000 people that had corrected their hearing loss versus 2,000 people who had hearing loss but didn't correct it, And they found very much the same thing that the people who corrected their hearing loss had less anxiety, less stress, were more sociable and were able to engage in conversations, much like these children you're speaking about now. They just all of a sudden have emerged. Now some people say, well, that's evidence that they're undergoing positive neuroplastic cognitive changes and that may well be, but I think what it clearly is the starting point is to remove auditory deprivation, right? In other words, now that they can perceive the sound, now they can participate. You know, hearing is perceiving sound, listening is making sense of sound. So what you're doing, I think, in your example is you're allowing them to participate in the acoustic world so they can thrive, And without that it's much more difficult.

Blaise M. Delfino, M.S. - HIS: 19:57

Dr Beck, we don't necessarily hear with our ears. we hear with our brain. Can you just tell us a few reasons why patients need to visit an audiologist or licensed hearing healthcare professional rather than just purchasing an amplifier online or over the counter?

Dr. Douglas L. Beck: 20:12

Well, so in medicine we have a rule, and every physician listening to this will recognize this It's called diagnosis first, treatment second. And this is a very, very important concept, because when you have hearing loss and you buy something over the counter or online, or you have listening difficulty and you buy something over the counter or online, there's no diagnosis, there's just an appreciation that you're having difficulty. And it could be that if you come into an office, somebody looks in your ear and they say you know, right against your eardrum there's a hair or there's cerumen, which is also known as earwax, or you could have a foreign object in your ear, you could have a torn eardrum, you could have a secular discontinuity which means that the malleus, the incus or the stapes, the three little bones in the middle ear, are not functioning properly. It could be that you have a dangerous hearing loss because there are some of those They're called retro cochlear, and that could be the sign of some sort of a brain tumor. Now I don't want to alert people and give you unnecessary fear, and you know they're not common, but they do exist. Every year all of us see a couple of patients who have an acoustic neuroma, which is also called a vestibular schwannoma. And that's the fear that many of the professionals have is that when people go direct to just purchase an inexpensive device, there's no diagnosis, there's just treatment. And that's the problem, because you know, once you've been diagnosed and we all know that you're okay, well then let's figure out what to do about that. But diagnosis first, treatment second. And most people are not aware of the fact that you can go into almost any professional hearing care office And you can probably walk out with a less expensive hearing aid, with one or two years of follow-up, with a diagnostic test, with somebody who knows what they're doing, who can program the hearing aid for you. It's probably going to cost you less than a thousand or twelve hundred bucks, and in some offices it's less. Some offices you can get out for eight hundred nine hundred bucks. But I think you're better off doing that with professional care than taking it upon yourself. I mean, once you know what you're doing, once you're experienced and you know that you're safe, then okay, maybe that's the time, if you have a mild loss, to explore some options direct to the consumer. Fine. But I think skipping that diagnostic step is not a good idea. Think about that in any other realm. Whether it's your teeth and you have teeth pain and you know, you just go ahead and you take Advil for it And maybe it goes away and you never have a problem again. So that's great. But maybe you need a root canal, and it would be really good to know that, because these things get worse if left untreated. Could be you have a headache. There's three things in medicine that we can't prove. We can't prove that anybody has a headache. We can't prove that anybody has lower back pain And we can't prove that anybody has tinnitus. These are all subjective complaints And you can't prove any of them. And so when you have a headache and it doesn't go away, maybe it's a migraine, maybe it's something much more dangerous. You know, headaches that go undiagnosed can become real problems. When you have back pain and you don't get a diagnosis, you can have a very, very serious issue. And if all you do is buy a brace or you take Advil or you take Tylenol or something over the counter, you can mask it, but maybe it's getting worse while you're masking it. And it's the same sort of fear with people who go and buy a product directly. It's not about the product. You have to understand. The primary benefit of a premium hearing aid is the services that comes with it, because you're going to an expert, you're going to somebody who's been trained for multiple years, is licensed by their state to manage this problem, and they're looking for all those red flags And if they say that you're okay, then you're probably okay. That's the whole reason. When we have licenses in every state in the union, it's not because we need to be licensed for our benefit. All state licenses are there to protect the patient. That's the goal of the state guidelines is to protect the patient. So when we go around that and we don't involve a professional, we don't really know what's going to happen.

Blaise M. Delfino, M.S. - HIS: 23:38

You're tuned in to the hearing matters podcast with Blaise Delf ino of Fader Plugs Today, we had Dr Douglas Beck join us again this week and we discussed cognition, audition, and amplification. Until next time, Hear Life's Story.