Innovations in Treating Minimal Hearing Loss – Dr. Brent Edwards, Live from EUHA

minimal hearing loss treatment edwards
November 15, 2022

In this special presentation, Brent Edwards, Ph.D., explores innovations in treatment for so-called minimal hearing losses. He discusses whether hearing professionals should recommend hearing devices to people with minimal hearing loss, and what research actually tells us about how well people with minimal hearing losses can benefit from hearing devices.

The presentation includes research findings from the National Acoustic Laboratories (NAL), where Dr. Edwards serves as Director, into these questions and into the potential use of emerging technology innovations.

We would like to thank the European Union of Hearing Aid Acousticians (EUHA) for allowing us to republish this presentation. For more information about EUHA, visit:

Full Episode Transcript

Speaker 0:18
When you say Future Friday you say innovation. And Mr. Brent Edwards is known for innovation. He’s done it with a lot of companies, GN ReSound Starkey, Sound ID, Earlens. And now he’s working for the National Acoustic Laboratories, the NAL. So we’re really excited to to hear you talk about your thoughts on the new future.

Brent Edwards 0:40
Great, thank you. Thank you very much. And I’d like to thank the organizers for the opportunity to speak and the invitation. So always a great pleasure to speak at EUHA, and to meet colleagues and friends. And if I may, I would like to dedicate this talk to the memory of Martin Blecher, who I always enjoyed at this meeting, talking about innovation and where our field is moving to, and who, with whom I’ll I will miss those conversations. So

let me start with a question for the audience. I have a series of audiograms on the screen, and I’d like you to raise your hand. See audiogram. Number one, the one at the top? How many people would recommend a hearing aid if someone showed up at your clinic, with that audiogram? Raise your hand? How many people would say you need a hearing aid? Not many. How about number two? Audiogram number two, the one in blue. How many would recommend a hearing aid for that person? Couple, how about number three? How many would recommend? Okay, so now it’s almost now it’s almost everyone. So this is this is how our world works. You know, someone comes in, we measure their audiogram, we make decisions about their need and whether we should treat them. Now my organization in Australia, we have a couple hundred clinics, we have a couple hundred thousand patients or clients, and 20 to 30% of the people who come into our clinics, we measure their audiogram. And they look like number one, they have what we would call normal hearing. So guess what happens with that person who’s come in asking for hearing help. The audiologist says, Congratulations, you have normal hearing. Come back in five years, and we’ll test your hearing again, goodbye. And that’s it. And I know this happens around the world. I’m sure it happens in Germany. And But it begs the question, why was that person there in the clinic? Why did they come in say that they have hearing difficulties and presumably asking for help? So I want to answer two questions that are related to this 1) Do these people who walk in with what I’ll call minimal hearing losses- do they actually need hearing help? Should we be concerned about them? And 2) if the answer to that question is yes. What do we do? What do you do to help someone who has hearing loss but who has hearing needs, but they don’t have any measurable hearing loss? So let’s let’s consider that first question. Do people with minimum hearing loss need minimal hearing loss need help? Well, let’s look at what the World Health Organization says about health disability in general, not just hearing but all health. They define health disability and the need for for health assistance, by what is your bodily function? What are your activities? You know, how do you participate in the world around you? But also what are the environment factors in which you live in? What about the people around you those social situations, your environment. So when we think about the audiogram, that’s the first dot point, the bodily function, but we really kind of ignore the rest when we make decisions on whether that person has hearing disability that we should be considering. Now two years ago, who published a landmark report on hearing that got a lot of attention. And this is a quote from that report, basically saying that hearing thresholds, the audiogram should not be used as the sole determinant of whether someone needs a hearing aid or a cochlear implant. That’s pretty powerful. When who says don’t do what we’re all doing. Don’t do what actually the whole world is doing.

In the US a couple years ago, there’s a taskforce that looks at all aspects of health care, and makes decisions on preventative health. How can we improve the health of our population? And they looked at the question, should we recommend hearing screening for adults 50 years and older? Now everyone in this room would probably say absolutely, as soon as someone gets in their 50s Everyone should get an annual hearing screening from their GP. Well, this group came to the conclusion no, that they did not recommend hearing screening for older adults. And the reason is because hearing screening fundamentally is like a simplified audiogram. And looking at the evidence, they concluded that pure tone thresholds and a screening would not be good at determining whether someone needs a hearing device or would benefit from it. That’s also very powerful. But we we all know this, we’ve known this for a long time. This is some epidemiological research from almost 40 years ago that shows that of all the adults who said they had a hearing loss 20% of them actually had normal audiograms. Now, on the flip side, almost half the people in another epidemiological study, almost half the people who actually had a measureable hearing loss, pure tone average greater than 25, said they had normal hearing, they didn’t identify as having hearing difficulty. So all of this begs the question, why do we use the audiogram as as our determinant of need and whether someone we should help someone and how we should help them? Well, I published this a couple of years ago, and in order in order to try to think about the world of people with hearing dysfunction, this column here are people who have what we would call normal audiograms Puretone, averages less than 25. This column here are people who actually have a measurable hearing loss, according to the audiogram, let’s call it clinical hearing loss. This row are people who, if you ask them, they say, I don’t have any hearing problems, I’ve got no hearing difficulty. This row here are people who actually say, I’ve got hearing difficulty, I’ve got hearing problems, speech and noise, I might have a hearing loss. So I estimated the numbers in the US for each of these groups. And in Europe, it will be very similar, a little bit higher, but the proportions will be quite quite the same. We consider the group on the right those who have a measurable hearing loss. And this is who we all consider the viable market for hearing aids. When we talk about this, only 30% of people who need a hearing aid have them is because we’re looking at this group as the total viable market for hearing it. So what are the numbers here? of the people who have a measurable hearing loss? Most of them 26 million in the US will say they don’t have any hearing difficulty. So why do we include this group in our target market in the people that we want to fit hearing aids on? And why do we say we’re not doing a good job, because we’re not fitting hearing aids on that group who don’t want a hearing aid because they don’t perceive to have any help. Like with any product, if you don’t have a need why would you get that product? So if you gave this, this group of people a hearing aid for free and put it in their hands, delivered it to their door, they wouldn’t use it, because they don’t perceive a need. So the real market for us is this group down here. So this is the group with a measurable hearing loss, they know they have hearing problems. And again, in the US that that group, maybe two thirds of them were actually fitting with hearing aids, so we’re doing a pretty good job. But there’s still quite a few people who have a measurable hearing loss. They know they have hearing difficulty, but they’re rejecting hearing health care for some reason. So that’s that’s an opportunity. And that’s something that we work a lot to try to, to address. And you know, in the US, OTC hearing aids are going to be one possible solution for this group. But what I want to talk about is this group over here, the people who don’t have a measurable hearing loss, but say they have hearing problems, and as I said, 20 to 30% of the people who come to our clinics in Australia, fall into that group. And in the US, I estimated the size of that to be 25 million, a lot bigger than the number of people who have a measurable hearing loss. Who know they have difficulty, by the way. So this is very large group of people who are being ignored. They’re not being serviced, solutions aren’t being developed for them. But they have a hearing need, but we ignore them. And we actually tell them, you don’t have any hearing problems, because they don’t have a measurable hearing loss, according to the audiogram. So does this is any of this making sense anymore? Hopefully, you’re starting to think about what you do and your practice and going, am I doing? Am I doing everything as well as I can here? And so that’s part of the message that’s gotten me thinking, how can we help this group? And, and what can tell us that they have a need if the audiogram isn’t. So there must be another way that we can, in a validated way, confirm that they have problems and validate their need. And you know, this, I think was beautifully summarized this, this arbitrary number of 25 dB pure tone average, that this paper talks about the history of where that came from, and indeed, it is rather arbitrary. There are reasons that it was created, and we have the categories of 25 and 40. And, and 70 for you know, moderate and severe. But this idea that if you’re better than 25, you’re fine. If you’re greater than 25, then you need a hearing aid is fundamentally flawed. And hopefully I’ve given you Little bit of evidence over the past few minutes of that. Now, Larry Humes, who’s an audiologist in the US very well respected, was thinking about this in a different way he was thinking about over the counter hearing aids. Now, if you’re going to get a hearing aid in a pharmacy or an electronic shop, without an acquisition or audiologist to measure your hearing, hearing, how do you know that you should be a candidate, you are a candidate for an OTC hearing it. So what what he concluded is a very reasonable approach is to use a validated questionnaire of hearing need. And he suggested suggested the H H. I. E. S, the hearing handicap inventory for the elderly short form, which is a questionnaire that’s been around for 40 years. 10 questions very easy to do, as possibly a way that people can identify whether you know, they are a candidate for hearing aid and should get one. So here are the 10 questions. And if you I won’t read them out, but if you just read any individual, you’ll see that these makes sense. These are the kinds of questions you would probably typically ask a patient or a client anyways, about their difficulty. But the difference here is this is a validated questionnaire, and you score each question between one and four, you sum it up, and you end up with an overall score between sorry, between zero and four, you get a score between zero and 40. The higher the number, the greater your self perceived hearing need. So what Larry Humes did is he looked at a large database of over 10,000 people where they had both the Audiogram and the HHIE score, and looked at the relationship between the two. So this is the HHI e score going from zero to 40. That’s where people up here, self assess is having no problems with hearing people down here, say they have tremendous problems in their lives because of hearing, this is their audiogram, pure tone average, going from zero to 70. So you see, generally, as the pure tone average gets higher, the HHIE score gets worse, but it’s not perfectly correlated. So what do we do, we kind of draw a line here at 25. And we say if you’re to the left of that, let me give you a hearing aid. And if to your to the right of that you don’t need my help. So what Larry suggests is, you might instead draw a line here, and say, If you score up here on this questionnaire, you’re doing fine, you’re hearing isn’t affecting your life, and you have no need. But if you’re down here, you’re struggling, there are things in your life that you’re hearing is causing problems, and how can I help. So let’s consider the combination of those. And so we obviously this group of here, no brainers they have hearing difficulty, and they have a hearing loss. Come on in let’s fit you with a hearing aid. But we also try to fit this group here, who also has a measurable hearing loss, but they have no problems at all. And we’re wasting our time with them, trying to convince them to get a hearing aid. And we talk about oh, it’s stigma. You know, they’re just in denial. You know, all these reasons why they’re saying no to your hearing aid, when the reality is they they don’t have a need, it’s not affecting their lives. But this group here down here, again, who I want to focus on, they’re having significant difficulty. They’re scoring tremendously high on these these problems in their lives from hearing. And even though they have a normal audiogram, they can use some help, they have the need. So the question then, of course, is, how can we help? So summary so far? audiogram shouldn’t be the only thing that we use to make decisions about someone’s hearing needs, and whether we should help them and that people who have this minimal loss need help. Okay, now, I’m going to move to the second question. What do we do about it? So if someone comes in, they got no measurable hearing loss? How can we help that person? Because there’s no guidelines for this? Well, we, we said we did something that we thought was crazy. We said, well, what if we fit them with hearing aids? So that’s exactly what we did. We recruited a bunch of people who said they had speech and noise difficulty, but they had no measurable hearing loss. And we fit them with high end Phonak RICs. Now we split them into two groups, we had the experimental group and they had fully functioning Rick’s with flat 8 dB insertion gain linear so that the amplified sound was above the sound coming through the vent, or the dome, with noise reduction with directional microphones and with beamforming or stereo zoom, I think Phonak calls it this group here. The control group, this was the placebo group, they got the same hearing aids, but we fit them with zero dB insertion gain. So No gain No features no noise reduction, but it was active. They didn’t know that this was a basically a non functioning hearing aid. And the reason we did that is sometimes when you do these experiments, people tell tell you that the hearing aids are amazing, even though they’re not working. So if we wanted to see a difference between these two groups, so we knew it wasn’t a halo effect, and the benefit was real. Okay, so we did a lot of data, a lot of data collection in the laboratory and in the field, these are the audio grams of the average of the group that we fit. Again, I don’t think anyone in the world hardly would recommend a hearing aid for this population.

So I’m just going to show you a little bit of data that we gathered. So we had a bunch of questions that we asked them about, they wore the hearing aids for six weeks out in the real world, we did laboratory measures of speech and noise. And we had questionnaires in the field questionnaires when they came back. This is an example this is the results from the control group with the 0 dB gain. These are the people with a fully functioning, hearing aids on these questionnaires, a score goes from one to five. So five means sort of a strong Yes. If you look at this question, Are you convinced that obtaining your hearing aids was in your best interest? The control group basically said no, the score is very low experimental group scored fairly high on that. Do you think your hearing aids are worth the trouble? Control Group- Very, very low score, they basically said no, the experimental group said yes. Think about that someone with no, no hearing loss, says the hearing aid was worth the trouble for them in their lives. Who would have thought that that would happen? So for me, the most fundamental question was, okay, now that the study is over, would you like to continue to wear these hearing aids because that’s for me, the bottom line did was a good enough, you want to keep on using them, going through the hassle of, of you know, changing batteries or recharging and all of that stuff. The control group, every single person said no. And when we asked them why they said, as we would expect, no benefit. uncomfortable, didn’t like them. About 60% of the group and the experimental people experimental group said yes, they wanted to continue continue to wear the hearing aids. And the reasons were, it helped them it helped in the situations where they had hearing difficulty. So that was, that was pretty amazing. Hearing aids can help people with no hearing loss enough that they want to use them even after they’ve worn them for a couple of months. But there’s more than hearing aids out there to help people with with hearing difficulty. These are some of them, shown here, whether they’re apps or attachments to iPhones or hearables. We look specifically at the Apple AirPods Pro. And these are the researchers who did this study, or investigated the acoustics of these devices. A couple of years ago, Apple created a feature that activated microphones on the on the outside, they call transparency mode. So you could hear the world around you while you’re wearing these occluding devices. We measured the insertion gain in transparency mode and you see a nice sort of zero dB insertion gain. So it really is passing the acoustics of the world around you, for you to hear. But last year, they introduced what they call headphone accommodation. And this turns air pods into hearing aids, adds gain and compression as a function of frequency, either with presets, you can select balance tone or vocal range, slight moderate or strong gain. Or you can enter the audiogram into your iPhone. And it’ll program the air pods for your specific hearing loss if you can believe that. So we looked and said, Well, what are these things doing, we measure the insertion gain from the air pods for the presets. Here you see the gain as a function of frequency for different stimulus levels for so for, you know, the gain goes something from 10 to 20 dB above 1000 hertz, which for a mild loss is probably not too bad. We entered some audio grams to see what they would do specifically for a specific audiogram. And we compare them to the NAL NL 2 prescription. So what you see here in the solid line is what the air pods did for gain as a function of frequency for the different levels of input. And the dashed lines are the now prescription the NL2 prescription. So this is what a hearing aid would do would be the recommended gain for hearing aids. And what you see is for speech level sounds 65, the the air pods are pretty close to the NL2 prescription. So for speech level sounds, they’re functioning very similarly to a standard hearing aid. For low level sounds, the gain is much less than what we would prescribe for high level sounds, the gain is more than what we would prescribe. So it’s not right on the prescription. But you know, again, it’s not it’s not that bad. We also measured the directionality and noise reduction. And just this is I won’t go to the details. Just to say these these can actually improve the speech to noise ratio fairly well with the technology in the air pods today. So this gave us some confidence that the air pods might help people if they have problems with speech and noise. And that’s exactly what we did. We did a very similar study to the hearing aids study where now with these popular this group of people with normal audiograms we fit them with air pods. And we said when you are in a noisy situation, you want to understand speech, put in the air pods, and see how they help you for so for six weeks, that’s exactly what they did. We did lots of laboratory measures of speech and noise and listening effort. And we, we have an app that called the NAL EMA app, where we can ask questions of them in the real world. So when they’re at a restaurant, they can answer some questions about how they’re doing. Here’s an example of the data that we got from this, we have so much data on this is incredible. One of the questions was, would you wear this device again, in the future in a similar situation? Or are there any reasons you wouldn’t? And so some of the people said, No, there’s no reasons I wouldn’t, I would do it next time. A lot of people said, You know what, I’m not getting much benefit, and so probably not, or I’m feeling embarrassed by wearing these air pods right now. And I wouldn’t want to do it again. Or they they’re uncomfortable, and they don’t fit. So that’s the kind of data we got from the field to understand how people are doing with their pods. We we asked used the SADL the satisfaction with amplification daily life, it’s a validated questionnaire that is used quite a lot to understand how people are benefiting from hearing aids. You can see the kinds of questions here, they’re pretty standard, you know, does it reduce the number of times you ask people to repeat themselves, you end up with a score from one to seven, the average for the air pods here was three and a half 3.3. And you can see the distribution here of the different people. Now when this survey was published in 2010, a typical hearing aid back then scored about a five. So air pods at three and a half are, you know, certainly on the low side of what a 12 year old hearing aid would would have done on the same scale. So not looking so good for air pods so far, I guess I would say. So that fundamental question, once the study was over, would you continue to wear your air pods in difficult listening situations? Of the 17 people? 12 said no. No, I wouldn’t. And and the reasons were, primarily, I wasn’t getting the benefit. So they weren’t helping. Or I felt really awkward and uncomfortable wearing them in social situations. Of the 17 five said, yes, they would continue to wear them. And even though they said it was socially awkward, but what they did to overcome that is they explained if they were with family and friends, you know, I’m wearing these things not because I’m listening to music, because I’m wearing them to hear you better. And that got over the uncomfortableness but you know, that’s not a situation you want to be in all the time where you’re constantly explaining why you’re wearing these things. So I think the visibility and usability of the air pods have a long way to go before they have a chance of really being accepted as an alternative solution for people with with speech and noise difficulty. That being said, last weekend, I was at a wedding. And lo and behold, there was someone in attendance, wearing air pods pros the whole time, as I talked to him. And he said that morning, it was a Saturday, one of the air pods was one of his hearing aids broke. And the clinic was closed. He couldn’t go to the clinic to get it fixed until Monday. And he was gonna not come to the wedding. And then he realized, why don’t I try this. So he put on the air pods. And he wore them for about five hours at the wedding and at the reception. And I kept asking him, how are you doing? Are these okay? He’s like, you know, they’re not as good as my hearing aids. But you know, it’s better than not, there’s better than nothing. And it’s better than just wearing one hearing aid. So as a as a temporary replacement for for a hearing aid. That was that was mind blowing to me, you know, what a what a great, what a great use for that. So maybe it’s not all the time, but in an emergency, it can help. So, to summarize, let me just say, let’s think of something other than just the audiogram in order to try to understand whether someone needs your help. When I presented this to a group of people in England, someone said, Wouldn’t it be interesting if you did the HHIE survey, in order to determine whether someone needed your help, and you only did the audiogram in order to figure out how much gain they needed. So you didn’t use it at all to to determine need or to explain what’s going on. You use their assessment of need in order to understand whether you should think of a treatment. That being said, people who have these normal audiogram can benefit from hearing technology, including hearing aids, if they have good speech and noise features. And finally, as I said let’s not let’s not just rely on the audiogram In order to determine who we should be helping, so thank you for your attention

Speaker 25:14
any questions?

audience 25:27
Well, thank you very much. Great. I thought it’s interesting that you said the stigma was like greater with the airport than with a hearing aid, which is like the astonishing is that so?

Brent Edwards 25:39
Yes, absolutely. So Well, first of all RICs are very discreet. Right? So there, it’s hard to see them anymore. So the idea that hearing aids are big and bulky and ugly, I don’t think really exists anymore. You know, we all say, well, people in kids in their 20s Kids, kids in their 20s are walking around with air pods all the time. Well, yes, they are. But people are in their 50s and 40s, who have some hearing difficulty. And when you’re at a restaurant talking to people or at a party. No, it looks it just looks rude. And it looks funny. Maybe we’ll get to a point in 10 years, where it’s commonplace for everyone to wear something all the time, but right now, it’s, it’s not socially acceptable. Yep.

audience 26:24
Thank you for your interesting talk. You showed the measurements of the outputs pro with moderate input level speech levels, okay for all standards, and therefore, the high input levels were low. If you’re going to a situation where you have a loud situation, a lot of people like the wedding and the input levels are low for high input levels, you have probably problems getting all information. Could you imagine that if you raise the input, or the gain for higher input levels, that they would benefit more from the airpods?

Brent Edwards 27:03
Well, so this population doesn’t need game, but what but the reason you give it game because you want the amplified sound to be above the unamplified sound coming naturally through the ear canal. So you always want some gain. Now we couldn’t control it in the air pods. It just does what it does. Now, if you have hearing loss, and you’re going to wear them to compensate for your hearing loss, which is probably a decent idea stigma aside, then then that’s probably correct.

audience 27:37
Okay, thank you very much. You

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Brent Edwards, Ph.D., is the Director of the National Acoustic Laboratories (NAL), where he is currently leading new innovation initiatives that focus on transforming hearing healthcare. For over 22 years he headed research at major hearing aid companies and at Silicon Valley startups that have developed innovative technologies and clinical tools used worldwide. Dr. Edwards founded and ran the Starkey Hearing Research Center in Berkeley, California that was a leading site for research in hearing impairment and cognition. Dr. Edwards is a Fellow of the Acoustical Society of America and an Adjunct Professor at Macquarie University.


The European Union of Hearing Aid Acousticians (EUHA) 

Since 1960, the European Union of Hearing Aid Acousticians ( has been in charge of organising the International Congress of Hearing Aid Acousticians (EUHA Congress). Over the years, the event has gained international renown, and is considered the industry’s most important specialist congress held in Europe. The EUHA is an association for all persons working in hearing aid fitting and supply. It provides a platform for hearing aid acousticians, scientists and laymen with an interest in trade-specific and economic issues, who wish to take part in specialised further education and vocational training in order to provide the best possible care for persons with impaired hearing. 


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