Kris Chesky: On Hearing Health, Earplugs, and How the Best Strategy for Protecting Young Musicians’ Ears Might Help Them Become Better Musicians Too

Noa:

So I thought I'd start by asking simply what is noise induced hearing loss, as in, if I were a musician and starting to exhibit signs of hearing loss, what are some of the first things I might notice? Is it difficult to hearing high frequencies or low frequencies, or maybe difficulty carrying on a conversation in a crowded restaurant? Like what are some of the things that I might notice?

Kris:

Well, I think it's important to distinguish noise induced hearing loss from just music induced, hearing disorders. Hearing disorders can include hearing loss, but it can also include other challenges to processing sound, interpreting speech, understanding timbral nuances in a musical sound, being able to discern differences in pitch. So I would just start by saying that there's music induced hearing disorders that are of concern. In fact, some of them might be even more of a concern than actual noise induced hearing loss, which is defined as having a change in your threshold of perception or changes in perception of sounds at threshold, which means that you need more energy to perceive sounds at a certain frequencies. For example, with somebody, with noise-induced hearing loss, to perceive speech patterns in a discussion inside of a restaurant, for example, typically the noise induced hearing loss is a change in the threshold at very specific frequency ranges, which typically fall within the 3,000, 4,000 Hertz bandwidth, which would be sort of top octave of the piano. So if you're playing violin or you're playing trumpet or something, and you have a decreased ability to perceive that set of frequencies in your sound, you might have difficulty matching others or aligning with what somebody else wants you to sound like. You can also see this probably the most common manifestation of this is when people are speaking to each other and somebody has noise-induced hearing loss, especially when there is a lot of other sounds going on.

Kris:

So it's harder to perceive those frequencies. And therefore it's harder to, to perceive and discriminate certain speech patterns, especially as it relates to consequences of speech. Right, so the S's and the T's, the Z's and all that stuff that has those, those high-frequency components become harder to pick up. And therefore you can't discriminate what the person's saying. You can hear them talking, you get the general idea, but those nuances become harder to to perceive. That's why somebody with noise-induced hearing loss is often looking for quiet places. And they get annoyed when they're in places where there's speech to just central to whatever you're doing and they can't pick up, or people are saying, interpret what they're saying correctly. I deal with this all the time, especially inside of a large lecture hall. I mean, I'm a trumpet player, so I can project and I don't need a microphone. And the students don't have any problem hearing me, but when they talk back to me and they're up in the stadium seating, 20 rows back, and they'll say something and I can hear it, but I can't quite interpret what they're saying, because I can't hear those, those nuances associated with where my deficits are in terms of frequency, specific changes in threshold.

Noa:

I think when you were speaking in Iowa, I remember hearing you describing your own experience of it in the way that you started to just now, do you remember how you started to find out that you were experiencing some of the sort of hearing loss? Like how did that come about? Because I mean, I was thinking about myself and we get our eyes tested every year. We go to the dentist to check our teeth. I can maybe think of a few times when I've had my ears tested, but I don't even know where that was or why that happened. I don't think checking our ears is a normal thing that we tend to think about. I'm wondering if we should be, or like, how does that you found out that this was happening for you

Kris:

Personally, this is one of my driving factors push me to address this issue is that yeah, I, I, I'm a highly trained musician and I was exposed to music education early level, early ages. And, you know, I started playing the trumpet in grade school was in the school band and middle school. I started to stick out a little bit and in high school I was class, I was lead. I was this and that, you know, playing professionally in high school and went off to college and ended up graduated from Berkeley college of music with a degree in jazz performance trumpet. And you've got my doctorate and all that. Nowhere, no at no time was I informed so that I would be aware of how my ears could be impacted by the musical engagement that I was involved with. And it was nothing, zero, you know, so for, for our, our musical culture, our, the discipline of music not to acknowledge this is a really important feature of what we do and what we don't do that needs to change so that when a young musician starts to steer themselves towards this... Or even, even people who aren't wanting to be a musician, but they consume a lot of music, right.

Kris:

They should be told somewhere in the educational system about this issue, so that they're not only aware and knowledgeable about how it works, they're competent to manage their, their lives, whether it's musical consumption or whether it's involving you know active engagement in music production, whether it's for leisure or for professional paths. And certainly in institutions like schools, you know, we should be very, very concerned about this in ways that again, would help prompt students. We do this here at UNT all the time in our courses, you know, go get your hearing tested. Why wouldn't you not want to know if you were at a, a slippery slope towards a problem early in life so that you can be aware and negate extensive exposures as you're moving forward, you know, what to do in response to that and yeah, get a checkup annually, because it's a slow, insidious process that you really aren't aware of until kind of like, man, I, how come I'm having trouble with that?

Kris:

And it may have started years earlier in a lot of times, I think musicians are so sensitive to sounds that their perceptual focus can override smaller changes in hearing sensitivity, sorta like a violinist or pianist who practice all the time and their hands become so amazingly dynamic and accurate and sensitive. And that's because they use this system over and over again, it's like an athlete. So they have greater, greater skill sets with that part of their anatomy. Well, same thing with the ear we train ourselves to hear with great acuity and sensitivity. We've learned to focus on sound and because of that focus, the threshold testing again, which is the way we understand if you have noise-induced hearing loss. I think for some musicians can, can actually override deficits because of their heightened acuity to sound. And I remember very clearly when I was at Berkeley in Boston playing in a band, it was an Elvis Presley impersonator up at the North shore.

Kris:

Jimmy Solona was his name, you know, it was a drummer in one of my ensembles at Berkeley that was in this band. And then something happened to this trumpet player and he asked me, Hey man, you want to do this gig? And I ended up calling to this Italian restaurant up in the North end. And it was just, there was three horns and it was great. And I ended up doing that gig for many months. Every week, and the band was set up against the corner of the restaurant with a little dance floor. And the stage was sort of in an L shape. The drummer was right in the middle of the corner. And then on one side of the drums was the guitar and bass player. And on the other side of the drums were three horns, sax, trumpet, and trombone. Well, the bass amplifier because the stage was not very deep was behind the horns.

Kris:

And on top of that amplifier, bass amplifier was the guitar amplifier, which is nearly at ear height right behind us. And I had no idea what was going on in terms of my health. I just, man, I listened to that guitar player. He sounds great. And it's just right in your face because it's, where are we? Right. I could lean back and touch it with my head. And I remember leaving that gig with this intense ringing in my ears, and it would not go away until I woke up the next morning. You know, it was tinnitus thing. Now I, if I was informed in school that, that is a clear sign of over driving the system. I would have done something about it instead, Hey man, it's not appropriate to have that amp, right behind our heads. You want to put it behind your head?

Kris:

Go ahead. I don't want it behind my head. You know, just simple things like that in order to be aware and call out practices that aren't healthy for anybody is a really important aspect of what we're trying to do in terms of changing the musical education culture. Yeah. And then yeah, getting tested. It should be an annual event. We have an audiology program here at school and we tell students routinely, go get your hearing evaluated every year. However, and I think one of the questions that you prompted me to think about in your email earlier was, you know, what are the prevalence rates for these kinds of things? What are the percentages of musicians that have this kind of stuff? That's a very, very difficult question to answer in large part, because it's difficult to understand the differences between shifts in your sensitivity and permanent changes in your sensitivity.

Kris:

So, and I've actually published papers on this. So we would measure, for example, threshold measures of students, right before an ensemble rehearsal, and then right after, and we would see significant changes in their hearing sensitivity after rehearsal. Now, was that permanent? No. Will it bounce back? Yes. Most likely. And, but it's, it's a recurring thing that the more that happens, the more likely you're going to have a permanent threshold chip. So what are the implications of that idea when you go get tested? Is that a musician or a student is very likely to go into the audiology clinic with some hearing sensitivity that does not represent their baseline, their state of hearing with abstinence of exposure to sound prior to that measurement. In fact, one of the interesting questions is how dynamic is our hearing sensitivity throughout even a day? How does this ebb and flow?

Kris:

There's not that much research about that because it's difficult to measure these things in time like that, but that's something that should be really important for a musician to think about when they do get tested. And it's really important for the audiologist to understand that what they're testing may not be a permanent hearing loss. In fact, the national Institute of occupational safety and health for industrial hearing loss concerns, the NIOSH standard for dealing with occupational hearing loss in regulated environments says that, yeah, if there is signs that the environment is sufficient to cause harm to workers hearing, then you're required to have testing of their workers. And if the first test shows that there is signs to have noise-induced hearing loss, the protocol is to reschedule and do another test like mandatory, like 30 days from now, you're going to come back in. But next time you come in, really be aware that whatever you're doing prior to the test could influence your sensitivity.

Kris:

You know, if you have to get in a car and drive to the clinic early in the morning, you know, you may not want to crank your stereo on the way over there, or you certainly don't want to do it in the middle of the afternoon after you've been teaching marching band in high school all day. So it's important for musicians to know that if and when they do go to an audiologist to get tested and they do get an audiogram that shows that there is a potential problem, they should be the one that speaks up and say, Hey, I want to reschedule for a baseline. And if you get the same thing twice, then it's more likely that that's a stable phenomenon. That's a really important piece, which does not occur by the way, in, in many situations, including those in research studies, there's been research showing how we tested all of these music students, for example, but where's the repeated measure? Where's the insurance of those things that would rule out the potential for this to be a short-term threshold shift?

Noa:

I want to make sure we go back to the, the idea that our sensitivity fluctuates based on how much sound exposure we've had prior to being measured. But before we do that I'm now curious about the measurement of sound in terms of whether we're practicing on our own or whether we're an orchestra, I guess, there are a bunch of things that occured to me. I mean, one, I think in your 2000 study, you found that there are different prevalence rates based on what instrument you play, whether it's acoustic guitar or whether you're a non-classical musician, or whether you play trumpet or voice or whatever the case may be. So that's one part of it, but does it matter where an orchestra is sitting in terms of how much exposure you might be having, or how much potential danger there may be to your hearing? If you're going to be measuring, do you measure near the instrument or near your ears or just somewhere in the room? Like, does it matter? Yeah, I guess I'm just curious about those sorts of things.

Kris:

Yeah. The measuring of sound as a, a step towards reducing risk, right? On behalf of the individual, or maybe even an institution or a manager or an owner of a company, it's very important in order to prevent. So knowing what sound energy levels are in an environment and what drives those levels, certainly distance helps. Right? So the further away you are from a sound source, there is a dissipating energy level just by virtue of it moving through space. So yeah, if we were in a big band and you were playing lead trombone, and I was playing lead trumpet, and the back of your head is literally a foot from my bell. That would be a problem for you compared to somebody off to the left or right. Or downstream. And this propagation issue by the way, is also frequency specific. So certain frequencies propagate in space different in terms of directionality compared to others.

Kris:

So lower the frequency, the more diffused the sound propagates versus the higher frequencies, which are the ones that we're concerned about in some ways, because that's where we get the noise, now it's more directional. So that only being further away being off axis could also help. But yes, the measurement of sound as a driver of change is a really important discussion. Unfortunately, the, the measurement of sound, as we conceptualize it today and conceptualize it really globally was developed specifically for understanding when an employer needs to respond to a work specific situation. Right? So when is it such that we have to kick in some preventative mechanisms? When does that occur? Right. So these studies were designed to figure out where a threshold was that would prompt some kind of response on behalf of the workers. And that's really important to, to keep in mind because that whole contextual framework was based on the idea that people in those work environments were going to be there every day for eight hours.

Kris:

And they're going to be there five days a week. And the projected risk is based on doing it for 40 years. So if, and when the worker is exposed to a certain threshold of energy for that full work day, then that prompts this response. And I asked you to list the types of things that are suggested to do they use the term recommended exposure limit. If the environment was regulated by OSHA, for example, which is the regulatory federal agency, NIOSH is the scientific driver. They have their recommended exposure limit. And then OSHA has their required, I'm sorry, PEL, permissible exposure limit. So you have permission to have this much sound before you do something, but once you reach this threshold, now you have to do something on behalf of the worker. So anyway, that modeling the research that underscores the decisions about where those levels are, were never thought through as it relates to musicians.

Kris:

So the sound energy itself in those environments is considered steady state, narrow band frequency, continuous noise that you might expect in a factory one. Two the dynamic nature of, and I'm talking about temporal dynamics, right? So the, the way the sound is over time is assumed to be pretty steady. So what a worker would hear at 10 o'clock in the morning is going to be pretty much the same at three in the afternoon, and it's sort of a routine type of, of sound is generated. So you got this temporal order, and then you have this dynamic contrast over time, too, in terms of the energy itself and the frequency specific range of noises that would occur at a factory, or a lot more narrow than you would have, for example, in an orchestra. So you have soft, loud and an orchestra. You don't have that in factory noise, you know, all these kinds of things. So there is a, there is an application problem, a

Kris:

Big problem. And NIOSH couple of years ago. In fact, that was part of this discussion with them, came out with a paper workplace solutions document that actually called out this particular issue saying that this 85 DB LEQ, which is the recommended exposure level for an eight hour workday is unlikely to be applicable to a music environment where somebody in school, might go to an ensemble for an hour, a day, for example, or a musician might go to a club and play two nights a week, and they're not doing it 40 hours a week. So that's a big problem. And it's a really, really big problem because a lot of times, most times the application of this is part of the discussion. And it's used to push musicians in, in certain environments and certain directions. And those directions are also consistent with what you might expect to occur in a factory without consideration of nuances that are driven by the musical act itself that could be simply adjusted to lower the level of energy reaching people's ears. I shouldn't say never, but it has not been a consideration because it's not a consideration in the recommendations to begin with. Give you an example. There was a study in Alabama where a high school band director contacted NIOSH up in Washington and said, Hey, we, we think we have a problem here at our high school. Would you give us some advice? So they sent two industrial audiologists to the work site. And for two days they took measurements and you asked about where the measurement should be by the ear or the lapell. And so there's different kinds of ways to do that, but it's like area dosimetry would try to capture sound generally in an area.

Kris:

So they did that and they concluded that after two days, the levels exceeded this criteria designed for workers who are doing it eight hours a day, 40 hours a week, 40 years of life. And he said, Oh, you exceeded that. And they attributed the excessive exposure levels to the room. Oh, you need a new band hall. It's not big enough. Or it's not high enough, or it doesn't have the right surfaces or whatever. And until you can figure that out, all your students should be wearing earplugs. Now, imagine two scenarios, one where the band director called NIOSH because he was worried that something negative could happen, including the possibility that he doesn't get a renovation of his building. He's in a city where money's being spent on band programs and the next neighborhood over there building a new band hall or a new school, or they're getting money for whatever. And he's not, and you say, man, this this room, not only does it smell bad and it looks bad, this can't possibly be sufficient for the sound that we're generating.

Kris:

And there, therefore, if I can show that we're over, over stimulating students, maybe I get a new band hall, like the other guy does, right? So now you're the guy that's coming in to take the measurements and you're sitting there in front of the ensemble and you're starting to kick them off and direct them. You know, what would you do in that scenario? You'd pull out those pieces that are the loudest most powerful. You would ask the students to play with really high level dynamics, short interruptions. You know, let's not spend any time at pianissimo during this rehearsal because we want to show that we're over the limit right. Now. What does that imply? It implies that the director has all the control, another scenario, a parent complaints, because they're kids coming home and saying, mom, you know, my ears are ringing. I think it's too loud in there. You know? And the band director is worried because the school boards, you know, all it takes is one little thing to shut that band program down. He's going, man. I mean, this is awful. So they're coming down to take the measurements. Now they're here, they're all set up. And he wants to show that this is not risky. So what is he going to do? He's going to pull out those pieces of music that they're the antithesis of the other stuff. Hey, let's play the ballads. Let's play it soft. Right.

Noa:

That was actually one of the most fascinating parts about I think your 2010 study that you did at North Texas with, I think finding that something like 40% of the events that you guys looked at exceeded the a hundred percent dose, but there was quite a bit of variation, even if it was in the same room. And you talked about how the instructor or the pedagogical approach that people were utilizing, had an impact on that sort of thing. I was going to ask you to expand on that, because that seems really fascinating. And like how aware do the band directors and conductors and so forth, or, or teachers need to be,

Kris:

They have, they have not yet been, I guess, informed sufficient..., You know, and plus historically, you know, the culture you don't go in there and question that maestro, you know, that that's off limits, even measuring these environments at schools is, is tricky because they know intuitively people who do this know intuitively that yeah, a lot of this is under their control, but they don't know how to control it in a way that actually leads to lower levels. Other than just doing things intuitively because they're not familiar with the measurement protocols are not familiar with how to analyze, the data and so on and so forth. And that's the other thing that gets back to the measurement is that the way you understand risk dose is to quantify sound energy over time. And you get a composite number that reflects the total energy generated over that time, irrespective of how it fluctuates in time. But if it fluctuates in time, you can really have a significant influence on the overall level. And that also brings up another concept that is central to the hearing conservation approach for hearing loss, which is considered the equal energy hypothesis. And that hypothesis suggests that regardless of what happened in time, the overall energy has an equal influence on hearing. So if I, for example, go into an environment that is industrial noise for example. And I measure for a period of time for an hour, for example, and I get an overall dose. And that energy level was in a narrow frequency range. It was very periodic. It didn't have much dynamic contrast, and it ended up with a certain level. Okay. And then I go into another environment and I, I end up with the same outcome measure, the same aggregate number as the industrial environment, but the noise was not industrial sound. It was classical music. So now you're going, wow, classical music. And you, if you looked at what happened in time, you would note that the highest energy levels in the classical music were way in excess of what the highest energy levels were in the industrial noise, even though the outcomes were the same. Well, if they're higher in the classical music, but it's still averaging out to be the same.

Kris:

That means they must also have lower levels. I see a more dynamic contrast in the classical music, as you would expect, pianissimo fortissimo versus just a sustained kind of periodic industrial noise. So they, they both have equal energy and industrial audiologist. And that whole approach to understanding risk would assume it's the same risk. Now there's been research that actually documents the influence of these differences on the hearing sensitivity of people. In fact there's a fascinating set of studies out of Germany, where they set up this experiment, where they had a group of healthy hearing, people measured before and then after, an hour's worth of industrial noise at this level. And as soon as it was over, they would measure their threshold and they would see, Oh, he takes more energy to hear a threshold. And then they would trace that over time for like the next hour and would see it restore back to normal.

Kris:

And they would see the time course for recovery. Then they did the exact same experiment, same equal energy level, right? Same energy level, but with classical music. And they measured the changes in the threshold of those people right after. And they noticed that the threshold was about half of what it was with the industrial noise. So the impact on hearing was dramatically different because of the dynamic nature. Well, we'll get into why, but the equal energy hypothesis did not work. Not only was the level like half in terms of the amount of shift, but the time course where recovery was also half. So in this particular author argued that the cochlea itself, which is, you know, the inner ear, the spiral shaped organ of corti thing that it has all these little hair cells in there. Well, if you unroll that thing and you laid it out flat, all these little hair cells are responsive to the very specific frequency ranges.

Kris:

So at the beginning of the cochlea, when the energy comes in is transduced energy from acoustic energy to mechanical energy, to hydraulic energy. So it's now vibrating through a fluid is tickling these little hair cells and the industrial setting, the hair cells along this kind of topically organized set of cells is a narrow band. It may be that band associated with what we perceive or have problems with the speech. For example, like the top optimism, you know, it's like, there's a band of hair cells that are getting stimulated constantly under this scenario, right? The other ones are not stimulated much because there's not much low frequency or really high frequency. And it's like playing a piano, you know, where you're just banging on those things repeatedly. Now, if you look at how the hair cells will be stimulated with classical music, you've got a broader range, just like the piano player playing the whole keyboard. I'm down here for a while that when there's getting a little rest, I'm going to play soft here and I'm going to play loud here. I'm going to go up here and it's all over the place. There's much more dynamism in terms of the, the energy distribution across that, that set of hair cells. And that may be why it's less stressed.

Noa:

That's, that's really interesting. It makes me think of something. I think a physical therapist or people in that area have talked about or recommended in terms of, if you have some really difficult, strenuous physical stuff on your instrument, do some of that for awhile, but then move on to something that's a little bit easier and not so physically strenuous. And then you can come back to, instead of like spending a huge chunk of time, just on that and potentially putting yourself at risk of injury physically, it sounds a lot like that actually, that maybe we need to think of our ears in a similar way.

Kris:

It imagined being able to operate as a musician or as a conductor, as a producer, composer and arranger with that sort of concept in mind where you're literally writing music or conducting or picking repertoire for a concert in ways that maximize the ability to play really powerfully. Wow, we're going to play Stan Kenton tonight or Count Basey are going to play Verity, right? That's going to be loud, but we can minimize the risk by making sure we have really powerful dynamic contrasts in our production huge swings of energy level and variety of frequencies and content areas around, you know, the, the full range of the musical expression we have. We can have a significant quantifiable influence on the dose. So the measurement of the energy literally comes down, even though the maximum levels go up because of this contrast over time. It's one of the most, I think, important and potentially transformational perspectives on how we do our music.

Kris:

So it allows us to create all the magic, but also gives us a way to control it so that we can minimize risk. I've got data. I don't think I shared it with you which really brings home the connection between this patterning of musical stuff in a school environment and the individual who's controlling it. So for example, just like that wind band paper that you look, we did a lot of that stuff. But actually a lot more with jazz bands. So we have, you know, a huge jazz program here. And we have a room that is set up for an 18 piece, big band. We have 10 big bands, individual, big bands, and they roll in and out of there like clockwork, they sit in the same seats, the same room, same genre, same educational mission. And when you start measuring it, you realize that there's a huge difference between the amounts of energy levels generated by different teachers.

Kris:

And one of the, in fact, this is quite a while ago, 10 years ago, or something, there was one individual teacher. I think it was a teaching assistant, you know, graduate student involved in the jazz program where the levels were through the roof. It's like, this is really high. And we literally had a discussion with that person. And they were like, Oh, what's the room is the music is how can I, you know, and it's, well, wait a minute, we have nine other events that occur in here routinely. And in fact, some of these other nine, bring it down to a really, really low level, even though they're getting louder than you ever got, they're using dynamics. You're not, right. You're not practicing your ensemble at pianissimo levels. Now ask any musician, what is the hardest thing to play? You go into a recording studio and you're getting paid by the hour.

Kris:

You don't have a chance to practice and rehearse and do it over and over again. And if it says play high energy, high pitch, and pianissimo, it's super hard to do that. It's really hard. I don't care what instrument, drums, trumpet. It's hard to play soft. It's a required skill for the highest levels of occupational engagement, right? It's a mandatory skill. Well, if you're not engaging those students in ways that get them to understand and practice and be sufficient at playing soft, you're also doing them a disservice in addition to allowing this thing to potentially harm their hearing. So by managing the music this way, you actually have a better aesthetic and anybody who's judging, like for example, bands in high school, you know, I don't know if you ever did anything like that. And you go and you watch a bunch of high school bands and you're rating them. One of the characteristics to rate is the use of musical dynamics in the more dynamic contrast it is, it's going to be rated higher. So you're serving lots of agendas by doing this.

Noa:

I like that angle of it too, because it, it again reminds me of sort of physical safety in that, you know, talking to people in, in Alexander Technique and Feldenkrais, and body mapping and so forth, you know, they talk a lot about minimizing injury, but at the end of the day, they're also saying this will help make you a better musician. Like it's not just about being injury-free, it's learning how to play with more ease and effortlessness and fluidity and utilize more degrees of freedom. And being able to, like you're saying, you know, play super quiet and super loud and really have mastery of that whole spectrum of dynamics makes you a better musician. So it's not just about preserving hearing, but cultivating these skills that are essential anyway. So, so I, I liked that they, they align and that sort of way,

Kris:

You know, let me, let me just follow up with that for a second, because of the 10 different, big bands that we we've measured over several semesters, there was one that was really unusual and it showed because we were getting a dose measure every day, over 15 week period. Right. So we could see how the dose would change. And we could actually see what nuances within each event influenced the dose. Okay. Which is really great. But there was one ensemble that started the beginning of the semester with pretty high level doses. And then over the course of the semester, they just kept coming down, coming down, coming down. And I have a chart of this and I have shown it many, many times. And I, I love the message that it sends, which is based on my discussion with the professor afterwards. And I went to talk to him about it. Dear friend, he's since retired. He has directed one of the most recognized collegiate jazz ensembles in the history of collegiate jazz. He was always the one that, wow, no matter for what semester, what year his ensemble always sounded great. It was just like magic. So I showed him this data and he intuitively immediately said, of course it goes down. I taught them how to play musically.

Noa:

So over the course of semester, they got better. And so that was reflected in their ability to play with more nuance. And that's awesome. Yeah. Yeah. You know, I'm wondering, cause we've been talking a little bit about ensemble and how the instructor has the capacity to influence the dose that students receive. How much of this is applicable when practicing alone. Like I'm sure it may be depends on the size of your practice room, but, but being mindful of that is important too. When we're practicing alone,

Kris:

Of course we've got some data especially like grand piano. We have a lot of piano majors and they get interested in this performing arts health area. And you know, we teach a graduate course specifically on this topic and we have pretty sophisticated technologies that we teach students how to use. These aren't apps. These are like, you know, $7,000 dosimeters class-A dosimeters. And we've had a run of students who are piano majors at the doctoral level, literally set up the equipment in their piano practice rooms. So you've got huge, beautiful quarter-million dollar grand piano, and same concepts apply when the pianist is playing with more dynamics, the levels come down and see in that to these piano players is, I mean, it's just like, wow, unbelievable. It really transforms their thinking about this. So ultimately we'd like to have every music room, whether it's an ensemble room or a practice room and this is true for like singers or trumpet players or whatever, if they have the ability to see what happened over time and the concept, and then get some idea of the consequences of that kind of practicing, not only on hearing health, but also on skill development, musculoskeletal, fatigue, vocal fold fatigue, whatever they would, they would have a solution to minimize the risk to all of that.

Kris:

So our idea is to eventually not, this is the future I think is to have sound smart campuses, nowadays technologies, used to be able to sense energy levels, wirelessly stream, to a master database archive, big data sets. And then you can go back in, you can analyze trends, you can see all of these nuances create tailored feedback based on smart learning algorithms to individual teachers or students. So it will literally tell you just like with the jazz, each one of those jazz professors, had a unique stamp in the data. Like for example, one professor may be driving the risk because they allow the ensemble to get too loud. Right? There is a level that, wow, okay, that's just too much. Right. And, but

Kris:

You don't want to tell everybody to do that because there's only one who does that. Whereas another director is more risky when they don't use dynamics, which is a measurement of kurtosis actually inherited distribution of time, spent at different dynamic levels. So you need a tailored way, you know, that represents the consequences of how they're doing their music. And the same thing can occur with individual practice sessions and it can be automated. In fact, we had a, a large NSF grant that we pushed out. Didn't get funded, unfortunately for several million dollars to build something like this in our school, so that it would all be automated. People wouldn't have to, you can take your cell phone, dial into the system and Oh yeah. What happened here, you know, today in this room and what's the trend over time. And now I'm adjusting, am I seeing it going down, you know,

Noa:

From what we've just been talking about, I might be assuming the wrong thing, but I'm getting an impression that the best way of protecting oneself or protecting musicians is to be mindful of range and how much time is spent at different dynamic levels. I received some questions from readers about earplugs and reading through some of your papers that my impression of that too, is that there isn't an ideal solution with earplugs. There's one question in particular that a trumpet player I believe submitted was when practicing, what are the best earplugs to use. And are there any that minimize bone conduction? Because I guess there are a lot of reasons why musicians don't like your plugs. So I wanted to pick your brain just for a few minutes on what more you can say about earplugs.

Kris:

I guess this conversation should also be contextualized to the origins of how earplugs are, are measured. So it's a product as a health and safety product that requires adherence to a protocol that allows the consumer to have some confidence in what the earplug does. So the FDA requires a certain protocol to meet here too. If you were to come up with an earplug and sell it to people as a protective device. Now the protocol itself was developed along with the recommended exposure limits and all that kind of stuff in light of the context and the type of worker that it was intended to be used by in the context that it was intended to be used, which is mostly industrial environments. So when they came up with this protocol, the protocol to measure plugs was not being considered for use to protect people from musical sources.

Kris:

That fundamental piece is a really problem. And so you would get a label of it on a near plug that tells you what you can expect in terms of the attenuation of the sounds, but because of the broader range of frequencies in music and the things that need to occur on behalf of the musician or the consumer of music in order to continue enjoying what they're doing and, or be protected this measurement protocol is just not sufficient to give you an example. So it's called the Real Ear [Attenuation] at Threshold measurement. This is the measurement that's used and required to put on a, an earplug product. This is a, a test that's based on people's perceptions of sound, similar to the audiogram. So it's measures of threshold, right? So I need that much energy at this frequency without the plug. And then I put the plug in and oh look that amount of energy needed now to perceive it went up.

Kris:

The difference between that without and with is the amount of protection. That's the assumption. Okay? And this protocol measures these things at various frequencies. And because when you use the bone conduction thing, you know, one of the problems with testing earplugs is due to the internal sounds that you hear when your ears are blocked at the occlusion effect. So when you're trying to measure very low frequency sounds with your ears, plugged, your perception is confused. It's confound it by bodily sound, your breathing, for example, even your heart rate, if you block your ears and you're really quiet, you can hear things. And typically low frequency things. So the ability to measure a low frequency perception at threshold with something in your ear is not reliable. It's not valid. And that's an established back in, in the literature for a long time. So therefore they start measuring earplug utility at 250 Hertz, and then they measure a threshold at octaves, so they go up to 500 Hertz and then they go up to 1000 Hertz. Well, that 250 Hertz thing is also below the frequency that is confounded by these internal sounds. So that that one measurement point is a problem. And some scientists argue that you can't do this kind of measurement protocol and come up with valid data below 400 Hertz. It's nothing about the piano, right? We tune the orchestra 440, right? You kinda know where that is a little bit to the right of the middle of the piano. Now imagine testing an ear plug in a way that does not account for any energy below that, which is what happens. So the earplug has not been subjected to tests that allow us to know how much energy is suppressed at frequencies below this level.

Kris:

Now, if you looked at the energy levels of a musical event across frequency, you would see that most of the energy is in that range. So if you plotted out energy across frequency, you would see this very, very steep slope of energy levels going from, you know, left to right low frequency to high, really high, to really low. We can't assume, but we can't integrate these testing protocols into models that are sufficient to understand how they work in a musical environment. And so we've developed some objective ways to understand how these earplugs work with music.

Kris:

So when we do start measuring the full range of frequencies with very detailed frequency-specific bands, like for example, the REAT measures energy at seven bands, the protocol we measured, I think it was 233 bands, right? So very discrete and specific. So we do this testing and with music and a simulated head and all this controls, we find out that sure enough, for some of these earplugs, they don't suppress the levels equally across frequencies. But the most common ones don't attenuate the low frequencies at all. So you're not getting the protection you need. And, and you're paying a price for the decreased perceptual ability that you need to play. So depending upon what instrument and all kinds of factors, you may be performing your instrument in a way that less than what you ultimately need or want.

Kris:

And you have to adjust your playing to accommodate with, you know, putting an earplug in your ear is like inducing hearing loss, basically. So you're, you, you have to learn how to play with hearing loss. Plus you have these other confounding factors related to the occlusion effect. So all these other things that are going on because your ears are, are blocked. There's also a challenge. Like for example, I'm a trumpet player. I can literally hear my tongue moving around and hitting the back of my teeth when I have earplugs in. And it's harder to tell what others around me are doing. It's hard to tell what my sound is in comparison to them. It's a real challenge. And unfortunately, the ingrained nature of all this stuff, you know, the dosimetry the measurement of sound, the measurement of earplugs, the protocols that people promulgated it, all of that is based on industrial audiology standards.

Kris:

And when they were developed, they were never intended to be in this environment, but we're stuck with that. At least we're continuing on that path, but at least exposing these challenges to a broader community, including those in the music community. So they're more informed when they see marketing materials. For example, you can go online and look at all kinds of documents, even from the government say, Oh, you're at risk when you exceed 85 DB, they don't say 85 DB LEQ, which is the equivalent of 85 DB sustained over an eight hour period. So the consumer is going, Oh, where's my DB app on my phone. Wow. This is over 85 DB. I mean, I talk over 85 DB, a lot of times, Oh, I must be at risk for hearing loss. That's not how it works.

Kris:

And then the same thing with the companies that sell ear protection. They ignore the idea that the rates of exposure could be dramatically changed by changing the musical behavior much more than an earplug can. And the other thing I think is really important to share with you and your audience is that the American Academy of audiology, which is the foremost voice in this kind of stuff, as it relates to hearing health, did establish a task force specifically to address these problems. And I was the only audiologist on that - non-audiologist on that task force. And we debated for a couple of years. And then I think it was 2019, we finished and we presented that to American Academy of Audiology and it was approved and adopted.

Kris:

And basically it was saying that audiology programs, training programs, like we call it the doctorate of audiology, the AUD degree, these training programs need to change. So we do have a brighter future by virtue of this new direction that we're calling for. So hopefully in the future, audiologists will be more aware of all this stuff as a professional competency, I guess, and this is globally important.

Noa:

So if you could wave your magic wand around and, and change things, I'm curious, what would you recommend or suggest to musicians? What would you love teachers to change in their behavior? What would you love to see amongst band directors and conductors, and then maybe administrators of music schools? What would be your take home message to each of those four categories of people?

Kris:

Well, my message would be to the music community that they need to own the responsibility to not only mandate that students who are getting trained as musicians are aware, knowledgeable, and somehow competent to manage this. It's our responsibility to manage our work. It's in our wheelhouse, it's in our, our sphere of concerns. Just like you wouldn't ask somebody else outside of the music discipline to write an arrangement for a band for you. Right. We would do that same thing. We need to control our production of music. So that's one thing. And then, you know, more importantly or specifically we need to figure out where these kinds of educational activities need to happen. One of the things that's happened, I'm assuming you read it is that we did encourage our national accrediting body for 650 schools to adopt policy, right? Adopt standards of practice that encourage if not mandate this kind of education to occur at tertiary level schools.

Kris:

So that's in play, but there's still a major deficit in that actually being set in practice. So we're in this transition stage. So we need more professors and people who are trained in this, which is why we have a graduate program here to do that. But because of that, and we're in Texas, right? So Texas has this behemoth music education phenomenon. That's probably the most robust music education scenario in the country, if not the world, as a representing a whole state. So our Texas education agency literally took hold of this idea and modified its requirements for all choir, band, and orchestra teachers from sixth grade through 12th. So there's a Texas education standard, it's called the Texas essential knowledge and skills specifically for fine arts teachers who do this, which says all teachers, choir, band, and orchestra teachers need to meet these learning objectives.

Kris:

And those learning objectives are about health-related issues associated with learning and performing music, including hearing health. So every choir director, band director, orchestra director should eventually be competent to introduce these ideas to kids, whether they're going to continue with music or not. So that they're aware and knowledgeable. In fact, the standards even suggest that not only do they explore these issues, they learn how to assess and they learn how to respond. That's really super exciting. A couple of years ago, we got a small NIH grant to actually develop resources for these, these kinds of teachers. And we've been working with our independent school district here in Denton. We've had several workshops and discussions. And, and those teachers are really interested. They intuitively understand the need to, to do this, but they haven't been trained.

Kris:

So they're not sufficiently empowered yet. And the other thing is that they want a very efficient approach to be developed. In the context of conducting band in junior high, when I have all these other things I have to take care of, how can I do this? And that's one of the the challenges that we have, but eventually all universities will be training future teachers to go out into the public schools so that they can embed this content into their educational activities in ways that minimize the downtime or whatever, just build it right in very efficient and effective.

Kris:

So it's pretty exciting time, even though it's challenging, especially in the hearing health area, because not only do we have the traditions of not addressing these issues, not thinking that we are responsible or liable even right. We have this other factor that's really hard to overcome, which is the embedded ways of thinking from industrial audiology. So we suddenly kind of have to stake that off. Somehow we have to diminish it. And it's not that these people who do this stuff, aren't well-meaning, they are very, very well-meaning.

Noa:

That sounds like not an overnight process, but one that will hopefully make for meaningful lasting change overall in the community. Anything I can do to get more people talking about it.

Kris:

Well tell them to get their hearing tested, make sure that they, if they do see a sign of concern that they schedule a revisit and get a real baseline, and then every year, keep track of what's going on and then look, literally look for audiologists that have a special interest in this. And there are some there's some programs and there are some specific individuals dedicated their careers to stuff like this. And thank goodness. And there's some real pioneers in audiology that need to be applauded.