Hearing Aid Programming: Pearls and Pitfalls

Imagine discovering that the key to optimal hearing isn't just in choosing a hearing aid, but in the precise individual calibration. This episode features a conversation with Dr. Ron Leavitt, a renowned audiologist who shines a light on the critical gaps in "best fit" settings provided by hearing aid manufacturers, compared to the National Acoustic Laboratories (NAL) targets. As we reminisce about our shared love for music and academia, we dissect the findings of Ron's study, revealing the transformative effect of personalized real-ear measurements on speech comprehension, especially amidst the challenges of noisy environments.

Hearing is personal, and the journey to perfect hearing aid adaptation is no less unique. This episode takes you through the science behind the NAL-NL2 fitting formula, discussing the artistry and precision necessary in calibrating hearing aids to this benchmark. We converse about the surprising variability in patient adaptation times, with compelling anecdotes that highlight the profound cognitive benefits associated with consistent hearing aid use. From the gradual adjustments in hearing aid settings to the promising advancements in remote programming, we underscore the synergy of audibility and comfort in this tailor-made approach to audiological care.

Ending on a note of reflection, we ponder the impact of professional occupation on cognitive decline, dispelling myths with hard scientific evidence that spares no profession. Join us for this enlightening discussion that not only promises to deepen your understanding of hearing aid technology but also offers a heartwarming look at how professional collaborations can enrich both science and personal bonds.

Transcript

Dr. Douglas L. Beck: 0:06

Good day. This is Dr Douglas Beck. I'm an audiologist and today on the Hearing Matters podcast we're featuring my dear friend, Dr. Ron Leavitt. Dr Leavitt received his BS and his MS from the University of Arizona and his doctorate from the Arizona School of Health Sciences. He is the recipient of the Larry Moldt and Award for Excellence in Teaching from Beltone, best audiologist in the western US from Rayovac and winner of the Audio Scan Challenge for Best Hearing Aid Validation Protocol. Now that turns out to be critically important in this discussion.

Dr. Douglas L. Beck: 0:38

During his 46 years in practice, dr Levitt has worked as director of audiology for the Tucson Unified and Amphitheater School Districts. Audiologist for University of Arizona Medical School. Instructor at University of Arizona Speech and Hearing Department. Director of the Austin Regional Cooperative for the Hearing Impaired Program at UT Austin. Audiologist for the Tacoma Public School System. Director of audiology at Iran obviously cannot hold a job. Director of audiology at Oregon State University. Audiologist for Good Sam Hospital in Corvallis, oregon. Senior instructor at Oregon State University. Consultant for the US Forest Service and American Bar Association for ADA American with Disabilities compliance and has been in private practice for 28 years and he's published numerous chapters and textbooks and periodicals. And, ron, it's great to have you. Thanks for joining me.

Dr. Ron Leavitt: 1:32

Thank you for giving me the opportunity. I always enjoy working with you.

Dr. Douglas L. Beck: 1:35

Oh, you're very kind, I appreciate that. So I, ron, I don't remember when you and I met, but I'm thinking it's been like 20 years, 25 years and yeah, and we're both musicians and I started reading. A lot of your work must have been about gosh back in 2011, 2012, and then I saw that paper that you did with Carol Flexer the importance of audibility in successful amplification of hearing loss. I wonder if you could just talk a little bit about that, because you did a survey of major manufacturers, and tell us what you did and what you found.

Dr. Ron Leavitt: 2:08

Well, at the time, as you know, there were six big manufacturers and they had, as they all do, a premium level, a medium level and a basic level of technology, and they, so we, asked them to send us their premium level of their most current technology and we, I, had a sense that the manufacturer's best fit was really not that best. So what we did is we first used the manufacturer's best fit, entering all the client data of hearing aid experience, use and age, etc. And then we looked to see how well they did on the bilaterally aided quick speech and noise test with these fittings, and we also looked at the real-ear data to see the extent to which they had achieved an NAL target, because we were using their software saying it was doing an NAL fitting. So we wanted to see how NAL it was, if you will, and come to find out it wasn't very NAL. By and large, they were largely under fit in critical frequency regions.

Dr. Douglas L. Beck: 3:20

And so this is such an important founding thought that audiologists, hearing aid dispensers, otolaryngologists, when you're going to a first fit and you haven't done a real ear, you may have a brilliant program and it may have been designed to perfectly fit NAL, nl2 or DSL5 or whatever, but if you don't have any due consideration for the real-ear anatomy of that ear, it's kind of a guess. It's a first fit, best guess, based on averages of hundreds and hundreds of years. That's great, but your ear is not average. Nobody has an average ear.

Dr. Ron Leavitt: 3:57

Old professor used to say if you put one foot in boiling water, one foot in freezing water, on average you're comfortable. But that's the problem with averages it doesn't apply to the individual, it's a group data and we'll talk more about that when we get to the Achieve study, which I think is important that we touch on. But be that as it may, so we look to see how these individuals performed with the best fit using the NAL target provided by the manufacturer software which, as I said, was not very NAL after all. It was really quite under fit in a number of critical frequency regions, almost across the board, on every single subject.

Dr. Ron Leavitt: 4:40

Which is rather startling, rather startling, yeah so you would expect then that, because we had not filled in all the gaps of aided audibility, that these folks would have problems on the quick speech and noise test, because here you have a female voice and you'll see from our data that they were particularly under fit in the high frequencies and you've got background noise, the two things that hearing aid users often complain about. I don't hear my wife well, I don't hear my grandchildren well, and in noise forget about it. So we expected there would be not as good a performance based on the real-ear data of these manufacturer generated alleged NAL targets and that in fact was the case. They didn't perform very well. But as I said to you, I used the six big manufacturers, premium technology at the time. But then as a foil and unbeknownst to the subjects, I also put in a 20 year old Siemens Infinity 3 analog single microphone, no noise reduction, single channel hearing aid as a foil and I didn't look at manufacturers best fit for that.

Dr. Ron Leavitt: 5:59

But I did program it to a full NAL target and we looked at the results with that hearing aid compared to the premium hearing aids fit to manufacturers best fit and, as you know, it didn't turn out well. Then we thought well, certainly hearing aids have advanced in the last 20 years, so let's program them to where we essentially fill in the aided audibility gaps. Which we did. We achieved an AL target on all the subjects. Then we just ran new quick speech and noise test in the bilaterally aided condition again to see how they did. In many instances and this is, I think, important information to manufacturers we were improving the signal to noise ratio loss in the magnitude of 12 to 15 dB, which is extraordinary.

Dr. Douglas L. Beck: 6:54

That's a huge, huge improvement.

Dr. Ron Leavitt: 6:56

So, and as you pointed out before, directional mics in the real world can't come anywhere close to that. So if you could just give good audibility, fill in those aided gaps, as I said before, you can have an immense benefit to the patient.

Dr. Douglas L. Beck: 7:16

Yes, this is, and to put some, and to put a handle on some of this, typical digital directional microphones, if well-fitted, are going to improve the signal to noise ratio by two or three, perhaps four dB, if the stars align, if everything's perfect, right. So when you're talking about double digit improvements in SNR, that's huge, that's unbelievably good.

Dr. Ron Leavitt: 7:43

Yes, so that got us thinking, though I wonder how pervasive this is. Our next study, I wonder how pervasive this achievement of the NAL target really verified NAL target is in the general populace, because we had been seeing a lot of people who hadn't been particularly well-fit. In fact, we'd been seeing a number of people who are wearing hearing aids that didn't have any benefit over the unaided condition, which gave us concern, and we'll talk more about that in just a minute. But we look to see. I wonder how pervasive this is, and first along comes Ryan McCrary, ruth Bentler and Patricia Roush, 2013.

Dr. Ron Leavitt: 8:30

Boys Town Emotional Institute yes, yeah, they say 55 percent of hearing aids do not meet their plus or minus five dB target at critical speech frequencies in children in nine different states.

Dr. Ron Leavitt: 8:43

So now I'm starting to get a sense that there's a national problem, not just a local problem. So then we got together 179 hearing aids on 93 patients from 24 facilities throughout Oregon and looked to see how close they were coming to that NAL target and because we'd already established that achieving it gives you some benefit by filling in the aided-audibility gaps in the previous study that we were just talking about and what we discovered was that 2.7 percent of those hearing aids were fit, using Ryan McCrary's five dB plus or minus target, to that NAL target. So we're showing even worse results with adults. Then along comes Sid Lowsky and her colleagues at Cleveland Clinic, and they are reporting that these people who are showing up for cochlear implants actually were not candidates for cochlear implants at all. They just had hearing aid programs that were doing virtually nothing for them, and when reprogrammed appropriately before doing the cochlear implant, they discovered they were nowhere near cochlear implant candidates. In fact, some of them were scoring 90 plus percent on the AZ biome and the bilaterally aided condition was properly programmed.

Dr. Douglas L. Beck: 10:09

So it's got me to Well, is it fair to say, then, that, in your experience, quite often 90, 95 percent of the hearing aids that are being worn out in the field are not being fitted to target and the patients are not really getting the full benefit of that fitting? However, I would bet that most of those fittings, the patients said, oh yeah, that sounds pretty good, and since the person fitting them did not fit them using real ear measures, they really had no idea how close they were or were not to the actual NAL, nl2, or DSL targets. Because if you're not doing it using best practices, if you're not fitting hearing aids using real ear measures, you're doing that other protocol, which I like to refer to as guessing?

Dr. Ron Leavitt: 10:59

Yes, and you and I had talked previously. You know I'm my minor was mathematics, so I'm always looking at mathematical implications and this maybe relates to OTC and professionally fit hearing aids. If you look at the average manufacturer's software, you'll see somewhere between four to 16 channels of adjustment and in those channels you'll see gain for 50 dB inputs, that's SPL, 60 dB inputs and 80 dB input somewhere around there almost universally throughout the big six manufacturer software. This is what you'll see and in each of those boxes let's just take an example that I used in a previous publication If you have nine channels and you have four levels of settings, you have gain for 50 dB inputs, gain for 60, gain for 80 and MPO control.

Dr. Ron Leavitt: 12:01

So in each of those boxes, if you assume you only have 10 choices and most of them have more than 10, but for ease of computation let's assume you just have 10 little choices you can make in each box If you then assume that somehow you're going to look into an NAL, a really verified target, you have a 10 to the 36th power likelihood of hitting that one in 10 to the 36th power. So that, like you said, guessing is generous. You know I can guess what the numbers on the lottery are going to be and I'll have a lot better chance than hitting an NAL NL2 target at those three input levels.

Dr. Douglas L. Beck: 12:46

That's a very, very important analogy. I'm so glad you mentioned that.

Dr. Ron Leavitt: 12:51

And I know that's what all that math did for me. That's one of the things I took away.

Dr. Douglas L. Beck: 12:57

All right, peter, go ahead. So then, in 2017, you did a article that was in hearing review, and this time it was Ron Levitt, ruth Bentler and Carol Flexer, and in that one you had that. That's. The study that you're referring to here is that 97.7% of subjects showed deviations from NAL NL2. In excess of 5 dB in both years, and you know, one of the things that people say to me often is I don't do any, I don't do real ear, because when I put it on target, people don't like it. What's your response to that?

Dr. Ron Leavitt: 13:35

They don't, and in fact I'm always a little bit amazed when I read in studies and I can think of three right off the top of my head that are very well published and have been discussed at length, but this part not so much. They take never new hearing aid wares, in other words people who have never used hearing aids, and they bring them to an NAL, nl2 target with mild to moderate hearing losses. So let's just concentrate on the moderate for just a minute. So let's say we got a 50 dB pure tone average. Okay, you're moderate by the Clark Asha method of computing and you would be maybe even into the moderate severe area if you're using the World Health Organization classification system. But either way, let's just take a 50 dB pure tone average in both years and you bring these people in and you set them to a full NAL, nl2 target. Yikes, and they wear it.

Dr. Ron Leavitt: 14:37

I don't. This is not consistent with my experience. If we tried that with people, they would have great difficulty on that first week, two weeks, month it varies wearing those things at all. So I'm always amazed by that and you really hit on something important If we believe that getting these people to this target is just going to be a one and done as Frank Leonard described it. Recognize that it's level and how I paved the way into. I think you're sadly mistaken. I think you're going to have a lot of people very unhappy and you're gonna have to work them into that with a lot of counseling and maybe even several programs where you step it up little by little until they get there, because it is very inconsistent with my experience that you can take a new user who has substantial hearing loss and put them in an NALNL2 fitting and have them walk away happy.

Dr. Douglas L. Beck: 15:42

So what's the right way to manage that? Because if you know that if you hit target they're not gonna like it, but you know the target is important because now you're filling in those audibility gaps. How do you approach that, ron?

Dr. Ron Leavitt: 15:58

I have a perfect example of one of my friends that's staying here with me right now, who has significant hearing loss. I've never worn hearing aids before and since she came from far away, we put program one at half NALNL2, program two at three quarters NALNL2, and program three full bore, and at her rate she can decide when she's ready to move up each step. And the beauty of remote programming, as you know, is that I can take, once she gets there, program three and move it to one, so and I can get rid of the other two and life is good.

Dr. Douglas L. Beck: 16:42

She's fully correct Go outside, go ahead. I love that. I think that's a great approach. What about adaptation managers? Because many of the manufacturers will have you know you can set a certain gain as the goal and you approach it slowly over multiple weeks. How does that work for you?

Dr. Ron Leavitt: 16:57

Well, my concern is that some people this takes a year, and some people I'll give you a funny example I have one of my audiology assistants who's a lifelong hearing aid wearer and she had moved to the coast of Oregon and her hearing aid had gotten broken. But she was so busy getting everything picked up and ready to move again that it would have been two months since she had worn hearing aids. And, boy, she's really severely impaired. So two months without hearing aids. And then she came back to work and so I said okay, let's get some new stuff on you and we'll put it on with that NAL, nl2 target that you've always used. Since you were a baby you've been NAL or DSLIO, but since your adult, teenage, adult life, you've been wearing NAL and L2. So I'm gonna get it. Put you right back. It's just been two months. Oh, no, the first day, oh my gosh. She said this is way, way too loud. Here's the punchline that was funny about adaptation. Though the next day she said could you give me just a little more? One day of adaptation? Okay, so there's the extreme. All my life I've worn hearing aids at a full correction, really verified and now I've been two months without it First day. Wow, overwhelming. There's no way I can do this tomorrow. Oh, can you give me a little more? So there's that. There's the one day I adapt her. But we've got a whole clinic full of one year adapters. So I would prefer to let them step at it there, and of course we're following them during this time, we don't just send them off. But I would prefer to let them move at their rate, because that is going back to our average result thing the freezing water and the boiling water in the buckets. On average it probably takes months.

Dr. Ron Leavitt: 19:03

In fact, glick and Sharma did a study and said that after six months they had achieved great findings and cognitive improvements with their subjects who had been wearing hearing aids minimum of six hours a day for six months, who were, by the way, at a full NAL, nl2 correction. So I'm good with it. And they also showed some cognitive benefits that had been obtained during that six month period and some change of resource allocation of the brain. Specifically, they were no longer using the memory and reasoning area to fill in the gaps on the bilaterally aided quick speech and noise test. They were once again using the auditory area. So reallocation had occurred in the six month period, but again, that's average subject time. And she said to me when I asked did it probably happen quicker for some and slower for others? And therein lies the problem. I don't know how quick it's gonna happen on anybody, and it's somewhere between one day and sometimes even more than a year. I think you're right.

Dr. Douglas L. Beck: 20:13

But the thing here is that each patient is an N of one. Each of them will adapt or acclimatize at their own rate and it's gonna be dependent on lots of factors that are uncontrolled variables. What is the conversation they're having? Who are they having that conversation with? Is it low stress, high stress? How are they doing with their hearing loss? Are we filling in the gaps? Have we achieved audibility? All of these factors that eventually lead to comfort and acceptance, and if you're just setting the hearing aid on full, on gain, I mean that's probably like driving your car at 110 miles an hour. It could probably do that, but it may not be a good thing to do that as soon as you get your learners permit.

Dr. Ron Leavitt: 20:54

Anyway, so Ron.

Dr. Douglas L. Beck: 20:57

I, you know we could talk about this stuff forever because there was that 2015 article. It was great. It was one more reason why pro-mic verification is crucial in any best practice protocol by Sanders, Judy Weber, Gus Mueller. There was that study by Mike Volente out of Wash U I guess that was 2018 or 2019, where they I'm gonna guess at this, I haven't looked at the study in a couple of years but they had maybe 20, 25 patients and they fit them all to first fit and the patients went about their lives and any of them said, oh, this is fine, Thank you very much. And then they brought them back and they fit them to real-ear targets and I think all but one patient said, oh my gosh, this is so much better.

Dr. Ron Leavitt: 21:43

Well, and you know, you reminded me of something I said I was going to comment on earlier. I was very impressed, as many were, with the Humes data of 2017. Yeah, larry Humes, yeah, he set three groups out with clinical tests and user self-reports of hearing aid benefit, and in one group he used the audiology best practices, meaning real ear verification and all that Valentin colleagues specified as best practice. Another group and this is you know not exactly what happened, but essentially picked out their own hearing aids based on some preset programs that probably would have been in the ballpark of what they needed. And then a third group where he put hearing aids on them with virtually no amplification. They were wearing hearing aids whose aided audibility and unaided audibility ratings by real ear were exactly the same. There was no benefit.

Dr. Ron Leavitt: 22:51

And here's the part that really impressed me. Let's talk about those subjects a bit. They were all adults, they had done cognitive testing. There was no cognitive problems in any of those subjects. There were 51 in each of the three groups and each of them had, on average, a master's degree. So these are highly educated people, financially secure and no cognitive problems.

Dr. Ron Leavitt: 23:15

Of those people wearing hearing aids with no amplification whatsoever, 37% said I will give you $1,800 per hearing aid for these hearing aids.

Dr. Ron Leavitt: 23:26

I'm satisfied, my performance is good enough for me. And that got me concerned and we see this a lot that yesterday we saw too People who are wearing hearing aids with no improvement in the unaided condition over the unaided and the aided condition over the unaided condition, and they've been wearing them for years, and one of them was a physician, one of them was a veterinary. So these are people, highly educated, no cognitive problems, young, youngish, you know. By my standards they were in their 50s, so this is not that uncommon. I'm concerned that there maybe are 37% of people in this country out there wearing hearing aids with no amplification whatsoever and quite satisfied with it. And this is getting back to what we were just talking about. If you try to push them up with amplification, I think sometimes you have a harder battle with them than you do with people who have never worn hearing aids and you're just starting from scratch because their norm has been developed very strongly for what sounds right.

Dr. Douglas L. Beck: 24:38

It sounds.

Dr. Douglas L. Beck: 24:41

And I think you hit on an important point is that many hearing aids that are actually out there malfunctioning nobody knows about right, because people are wearing them, because they're used to them, they think they're supposed to wear them and they are, but the hearing aid not hitting target or malfunctioning is a very, very difficult thing for a user to be aware of. But my concern was always for the patient is that you know, in medicine what we always say is diagnosis first, treatment second, and when we're allowing the patient or encouraging the patient to self-diagnose, I think we're going to have a lot of missteps.

Dr. Ron Leavitt: 26:01

I agree with you completely and many of my colleagues do. That is, diagnostic audiology has existed for these many years because it is providing a very important service. We don't know what we're fixing until we know what the problem is. So I'm completely with you on that. And then, by fact, you and I and Carol have an article out on this subject.

Dr. Douglas L. Beck: 26:26

Yeah, we do. Yeah, it came out in August of 23, and I believe it's in the hearing review. Ron, and then, before I let you go, I know you've been involved In another large survey research project. I wonder if you could just encapsulate that for me in the next couple of minutes. What did you recently research and what were your findings?

Dr. Ron Leavitt: 26:47

Well, you know, in the study where we looked at the fittings of hearing aids in Oregon, we had a few people from other states. We get people from a variety of places at our clinic and there weren't enough of them to really put them into the data set. But as time has gone by we've gotten more and more people in that data set. So we're now starting to look at how well our hearing aids fit on adults across the country and we're getting more states in the data set as well as more people from Oregon, and the results are not encouraging in terms of the quality of hearing aid programming. The real aerated measures for people in states other than Oregon. These adults that we're seeing are not any better than what we're seeing in Oregon. And I want to get you know we had 93 patients from Oregon from 24 facilities, 179 hearing aids and well above that. We're in the 300s now for people in Oregon.

Dr. Ron Leavitt: 27:57

So our data set has expanded considerably and we are able now to look a little bit at some of the neighboring states to see how well hearing aids are fit, because people move to Oregon for a variety of reasons and then we have their hearing aids fit in these other states where they've come from, and it gives us an opportunity to see how pervasive this poor fitting or this underfitting, if you will so I don't put a value judgment on it this underfitting of hearing aids is how common it is, and it's not just an Oregon problem, as Ryan McCurry told us with children, but the problem with adults, I think, is even more significant than he reported for children.

Dr. Ron Leavitt: 28:44

He said 55% of hearing aids didn't match their criteria of an adequate fitting. Our numbers are, as you know, much higher than that and continue to be much higher than that. And as soon as we get enough of the other states and the data set swells to a sufficient level to have lots of power, we'll be publishing that again. But what I am seeing is from what we've seen over the last it's been six years since that publication is that things haven't gotten any better at a national level.

Dr. Douglas L. Beck: 29:19

Previously. We're about 95% 97% underfit. Is it still looking like we're in that ballpark? Yes, yes.

Dr. Ron Leavitt: 29:30

And there's a large number of people who are wearing hearings with no improvement in aided SII over unaided SII.

Dr. Douglas L. Beck: 29:38

Yeah, and that's speech intelligibility index. What are your take-home points, Ron? What would you say that the average hearing aid dispenser audiologist ought to be paying attention to?

Dr. Ron Leavitt: 29:50

Well, you and I have been talking about this really or aided thing since we were a little younger. When we started that discussion I remember sitting Mead Killian and I were in San Diego and we saw the Rastronix real aided measurement system and we said you know, I think this was 79. We said you know, this is going to make everything we do obsolete. We're going to be doing this on every hearing aid. We were so wrong.

Dr. Douglas L. Beck: 30:23

Well, the Rastronix was one of the very first systems out there.

Dr. Ron Leavitt: 30:26

And it was really, we were impressed.

Dr. Douglas L. Beck: 30:29

Yeah, I remember being very excited by it as well. But if you were to say to an average hearing care professional, this is the problem that we have quantified in essentially a national database. The problem, specifically, is that hearing aids are being underfitted. Is that fair to say yes, and what we recommend is what would you Filling?

Dr. Ron Leavitt: 30:54

the aided gaps.

Dr. Ron Leavitt: 30:55

And you know, Filling the aided gaps yeah, I'll go back to my colleague and mentor, james Jurger, and his lab assistant Theland, who's in 1967, 1967, there were no real-ear systems. But what they did is they looked at the two CC coupler outputs of various hearing aids and they discovered that those hearing aids too had very peaky and valley responses. They called it the index of response irregularity. Those that had a very irregular response were yielding poor scores on the aided, a synthetic sentence index of theirs. So that speech and noise, in other words, their findings were that even the two CC coupler data was telling them in 1967, 1967, that if you have these gaps, these aided gaps, it's going to compromise speech, understanding and noise. Well geez, they were about 50 years ahead of their time.

Dr. Douglas L. Beck: 31:57

Let me ask you one last question before I let you run In the recent publications that have come out on the Achieve study, because when I initially read the article and I did a series of interviews with Dr Jennifer Deal, the epidemiologist at Johns Hopkins, we were talking only at that point about the people who were actually in the primary study, which was looking at people who received excellent counseling versus people who received amplification In that part of the study. I believe they all had premium hearing aids. What they found is no difference that excellent counseling, really good health awareness counseling, and well-fitted hearing aids both benefited the same, which I think makes good intuitive sense to me. However, as you were saying, the people who are most at risk for cognitive decline people with lower socioeconomic, people with less education, people with comorbid factors those are the people who, when fit appropriately to NAL and L2 targets, they had 47-48 percent less cognitive decline over the three-year period, if I'm saying that correctly. I hope I am.

Dr. Ron Leavitt: 33:12

Well, as you know, jennifer Deal is quite a statistician and insists that we make sure to clear to people that that's again average population data. For the individual it doesn't apply. But I would say this about that this is where she and I differ a little bit. I would say, if you tell me that there's a chance that I would have a 48 percent protection against dementia, even if I may not be on my individual that risk, chance of risk protection I would still go ahead and put the hearing aids on and insist on a full correction.

Dr. Douglas L. Beck: 33:53

Yeah, I think that's a fair analysis. I'm glad you made that point, and I think this also gets to the fact that when you have a 35-year-old patient who's got a PhD in electrical engineering and they're at the executive level in their company, they're not the ones we're talking about. It's really the patients who are most at risk. They are the ones who I think we have to focus on for these benefits. I don't think that I would say to that same PhD electrical engineer gee, you're at risk for cognitive decline. I mean, maybe they are, but the data that we have shows that it's other people, it's not that guy or that woman. So I think we have to go with the science on this and it's always good to under promise and over deliver. Yes, yeah, all right. Well, ron, it's a joy to speak with you and I'm so glad for our friendship and for your academic pursuits. I want to thank you for joining us on this edition of Hearing Matters podcast and I will look forward to seeing you sometime in 2024.

Dr. Ron Leavitt: 34:54

Always a pleasure, my friend, good to see you. Thanks, take care Ron.