MAIKEN SCOTT, HOST: This is The Pulse — stories about the people and places at the heart of health and science. I’m Maiken Scott.
I have this really vivid memory of a trip that I took years ago to New York City. Old family friends were visiting from England. They were originally my parents’ friends, and then I got close with them when I spent time in the UK as a teenager.
So I took a train from Philly, and I was so excited to see them. It had been years. They picked me up at the train station. We hugged. We said our hello’s. We were trying to catch up, but it was just so loud. I mean, of course it is. It’s a train station.
So we moved on to an outdoor cafe nearby. We grabbed a table, but it was loud there, too. Traffic was going by on all sides. There was a musician playing on the sidewalk. People were yelling and talking.
Eventually, we went to a restaurant for lunch. We walked in. There was only a few other guests there, and it was really quiet, and I thought, ‘Ah, finally we can sit down and really have a conversation.’
Then somebody starts playing music on the jukebox, and a huge group of tourists walked in. They were all talking all over each other, and then it was super loud in there, too.
And it’s funny because my dominant memory from that day is not getting to see my friends or even what we talked about. It’s this feeling of being surrounded by noise and just trying to get away from it.
[MUSIC]
MAIKEN SCOTT: For a lot of us, especially if we’re living in cities, noise is a constant factor. It’s a never-ending soundtrack playing in the background — traffic, buses, trains, planes flying overhead, sirens from ambulances blaring by, construction, people yelling. We block it out when we can, or maybe wear headphones playing music or podcasts.
All of that noise can actually be damaging to our hearing and also our overall health. Researchers are learning more about the connection between hearing, hearing loss, and our well-being.
On this episode: Noise and living in a loud world.
[SOUND OF U.S. NAVY BLUE ANGELS TAKEOFF SEQUENCE]
RICK NIETZEL: The loudest place I’ve ever been in my entire career was standing on the flight line at Boeing Field in Seattle, Washington, when the Blue Angels took off in formation.
MAIKEN SCOTT: That’s Rick Nietzel. He studies noise exposure at the University of Michigan. He was at an air show measuring the noise levels of this famous Navy fighter jet squadron.
RICK NIETZEL: It’s astonishingly loud, over 140 decibels to the point of being painful, and also essentially shaking my entire body with so much acoustic energy. It was something to behold.
MAIKEN SCOTT: Rick is a professor of environmental health sciences, and he picked noise exposure as his focus because he felt like it wasn’t being studied enough, especially given how important it is for our health.
INTERVIEW:
RICK NIETZEL: Noise exposure is something that is really ubiquitous. All of us have it virtually all the time. But there are very few folks, at least in the United States, who are actually doing research to better understand it. But it has proven to be an endlessly fascinating exposure that, unfortunately, this country has largely ignored for the last 60 or so years.
MAIKEN SCOTT: And is the reason that we ignore this or tend to ignore it the fact that we can kind of kick the can down the road? You know, sometimes we’re somewhere really loud and then we have an immediate impact on our hearing where we’re like, ‘Whoa,’ you know, like my ears are ringing or I’m having trouble hearing. But usually this effect accumulates over time.
RICK NIETZEL: It does. The primary health outcome that we’ve associated with noise over time is noise-induced hearing loss. And it’s very insidious. You don’t notice it in most cases happening because it’s happening over the course of months and years and even decades. And the rate is slow enough, and the change is subtle enough, that people simply don’t realize until maybe decades later. People are asked then, ‘Why do you listen to the television so loud?’ Or, ‘Why do I have to shout to talk to you when we’re in a crowded environment?’
Now, I will say there’s now a pretty convincing body of evidence demonstrating that noise exposure isn’t just bad for our hearing. In fact, it’s bad for our cardiovascular systems. It’s bad for our mental health. And there are a lot of other outcomes, honestly, that might make hearing loss look like just the tip of the iceberg. I’m hoping that as these findings come to light, noise will become more and more of a recognized problem and will actually take steps to deal with it.
MAIKEN SCOTT: And what is the connection to heart health? Like, what is actually happening?
RICK NIETZEL: Yeah, there’s a couple of sort of prevailing theories here. One is we know that noise exposure at night causes disrupted sleep, and sleep disruptions turn out to be very strongly predictive of cardiovascular disease.
As a second pathway, it turns out that workers who are exposed to loud noise during their work shift are also at increased risk of cardiovascular disease. The theory here is that noise during the day is simply a general stressor on our system. And when we’re working in loud noise, we’re essentially activating our body’s fight or flight mechanism. Again, occasionally that’s not a bad thing, but if your body is in that excited state constantly while you’re at work, that can lead to those same negative cardiovascular outcomes.
MAIKEN SCOTT: When we’re talking about noise exposure, can you give us some examples about how loud is too loud, and what kind of time frame are we talking about for the exposure?
RICK NIETZEL: Yeah, so we actually have a fair amount of data that allow us to determine what a quote-unquote safe level of noise exposure is. And there’s broad scientific consensus that if people’s average noise level over time is at 70 decibels or less, and that’s about as loud as a quiet vacuum cleaner or maybe a conversation happening with someone an arm’s length away. So this is not an extreme level. But if people can stay at or below that level on average over time, we’ve essentially eliminated any risk of noise-induced hearing loss, even among most sensitive individuals.
Now that doesn’t mean you can’t go above 70 decibels. So, for instance, if you’re out mowing the lawn with a gas-powered lawn mower, that might be 90 decibels. If you’re operating a chainsaw, that could be 100 or 105 decibels. Certainly, gunshots can be upwards of 130 or 140 decibels. So it’s not to say you can’t have exposures like that, but we want to make sure that if you have loud periods like that, you also have quiet periods that allow you to bring that average down to 70.
Now, the higher people get above 70 decibels on average, the greater their risk of hearing loss. So all of this is to say it’s actually fine to have short-term exposures to reasonably high levels of sound. We just want to make sure that those are offset with quiet periods to allow the ear time to recover.
MAIKEN SCOTT: And what actually happens when we’re exposed to really loud noise?
RICK NIETZEL: There’s actually two different ways that high noise can harm hearing. One is pretty uncommon. I’ll start with that when it’s called acoustic trauma. And this is when noise is so excessively loud. We’re thinking things like gunshots or explosions. The levels are so loud that they actually physically damage the middle ear bones and the tiny little hair cells in the inner ear that actually allow the brain to detect sound. So with that acoustic trauma, those structures can simply be physically obliterated in a single fraction of a second from an explosion, for instance. So that’s very common in certain settings like the military and combat.
The risk for most of us is for so-called sensorineural hearing loss. Those same little hair cells that reside in your inner ear, each of which is listening for a specific frequency of sound, those hair cells, if they’re exposed to excessive amounts of sound over chronic periods or long periods of time, those hair cells can basically suffer metabolic damage and slowly wither away. And unfortunately, once they’ve been damaged enough, they will not recover.
And so that’s why I say for most folks, the risk of hearing loss is not, it’s going to happen today from a single event, but rather it’s resulting from chronic exposure over months or years or even decades, and this sort of slow, insidious damage to those inner hair cells.
MAIKEN SCOTT: Okay, so me going to a Motorhead concert once, where it felt like I lost my hearing, probably wasn’t as bad as I thought. But then going to lots and lots and lots of shows in small venues that were really loud, that probably could do some damage over time.
RICK NIETZEL: Yeah, so it turns out having a single loud event, unless it’s exceptionally loud, like I mentioned, explosions or gunshots, your hearing can tolerate that it can recover. The thing with any environmental hazard, this would apply to chemicals or noise, just as readily, is that it’s not just about how loud it is, it’s about how loud, but also how long the exposure is, and then how frequently you have the exposure.
So an occasional concert is going to be fine for the vast majority of people. I will say many of us, myself included, have probably gone to a show, maybe a Motorhead concert, maybe something else, and maybe experienced a sensation after the concert that their hearing was muffled or it sounded like they were underwater, or maybe had a sense of fullness in their ears. That’s really our body’s only way of telling us, ‘Hey, that was too much sound.’ You’ve essentially temporarily damaged your ability to hear, and that will typically recover within 24 hours or so.
MAIKEN SCOTT: Yeah, yeah, but it definitely is that feeling like, alright buddy, don’t do that again, please.
RICK NIETZEL: Absolutely.
[MUSIC]
MAIKEN SCOTT, HOST: That’s Rick Nietzel. He’s a professor of environmental health sciences at the University of Michigan School of Public Health.
We’ll hear more from Rick later on in the show, but now let’s take a closer look at live music and how it affects our hearing.
[MUSIC]
MAIKEN SCOTT: For many live music fans, the motto has always been the louder the better, right? But these days, you do see more concert-goers wearing earplugs. And some people are wondering, does the music have to be so loud?
Alan Yu has more.
[MUSIC]
ALAN YU, REPORTER: When I talked to musicians and people who run local music venues in Philadelphia, everyone had a remarkably similar story about how they started wearing earplugs to concerts. There was a time before.
ANNA REED: When I was 18 and 19, I don’t think I cared about it all that much. I was like, the louder the better.
ALAN YU: That’s Anna Reed, general manager of the independent venue, Milkboy.
TARIK SHAPLI: Nobody wore earplugs back then. My first concert was Black Sabbath. My second one was Led Zeppelin.
ALAN YU: Tarek Shapley, guitarist for the rock band Tone Bandits.
TARIK SHAPLI: Big loud shows and nobody ever thought about it. It just wasn’t a thing.
ALAN YU: And Drake Tyler, drummer for a band called Song People.
DRAKE TYLER: You could come up with various reasons why you wouldn’t want to look like you were putting on a bunch of safety gear until I go to a show or whatever.
ALAN YU: And everyone told me that in one way or another, after years of going to shows blissfully unaware of how dangerously loud the volume can be, they started to notice the impact. Here’s Anna from Milkboy again.
ANNA REID: Being at a show every single night, I kind of started to realize, like, oh, this is like constant exposure to like high levels of sound. I should probably protect my ears.
ALAN YU: Anna’s colleague, Sean Svadlenak.
SEAN SVADLENAK: I got tired of coming home from a loud show with ringing in my ears and now knowing like that little cilia in my ear is never going to work again.
ALAN YU: And Benjamin Schurr, bass guitarist for Song People.
BENJAMIN SCHURR: I was at a house show, I used to live in D.C., and you know, it was a kind of a culture of people having shows at their houses. And there was a punk house that I went to, and they were like, I hope everybody brought earplugs and then managed to play this like crushingly loud set of music. And I was like, ‘Oh, I’ll just put some toilet paper in my ears.’ And I have got permanent hearing damage in my right ear from that night.
ALAN YU: Earplugs change the concert experience, but there are specially designed earplugs now that are made such that the music will still sound good.
Sean is the production manager at Milkboy. The venue often puts on several shows a week. He says there is a simple logistical reason why concerts have to be so dangerously loud. On stage, the instruments and vocals are competing with each other.
SEAN SVADLENAK: It has to be louder than the next loudest thing. And that applies even with no one in the room. So if you want to hear every word or syllable your favorite singer is singing, that all has to be louder than the snare drum on stage. It has to be louder than the crash cymbal.
[SOUND OF JOHNNY BRENDAS EMPLOYEES AND TALENT DOING A SOUNDCHECK FOR AN UPCOMING SHOW]
ALAN YU: Production managers do sound checks before concerts to get the mix right. Johnny Brendas is an independent music venue in Philadelphia. It fits around 250 people.
Singer Shaina Kapeluck from the band Song People is on stage testing the volume.
ALAN YU: And here is Shaina singing, but with the two guitarists and a drummer playing at the same time.
[SOUND OF SHAINA KAPELUCK SINGING]
ALAN YU: Engineer Jeff Sarafinas is running the sound board. He adjusts the levels and explains what he fixed.
JEFF SARAFINAS: Definitely an indie rock band, but with a quieter, like intentionally quieter, vocal. And a lot of times that happens, and it sounds awesome on a recording. And it can sound awesome live too. I think they just needed more vocals on stage because the instruments themselves were loud and then it’s a quieter vocal. So I just had to turn that up.
ALAN YU: By the last sound check, it sounds like this.
[SOUND OF SHAINA SINGING OVER INSTRUMENTS]
ALAN YU: So there are logistical reasons why live concerts are loud. But concert goers also tend to like loud music. Back at MilkBoy, Anna Reid loves heavy metal.
ANNA REID: One of the things that draws me to metal music is that when it’s so loud, you can’t hear yourself think. Instead of being like a hype up kind of experience for me, it’s like a relaxing and calming experience for me.
If you’re worried about something, if you’re sad, it kind of just like doesn’t let you think about it because your ears are being totally flooded and your brain is being totally flooded with just like an overload of sound.
ALAN YU: In 2017, David Welch, a professor of audiology, looked into why people like music that they either know or suspect is too loud to be healthy for them. He’s at the University of Auckland in New Zealand.
He worked with a colleague to survey guests and employees at nightclubs. He says people learn to associate loud music with fun, like how Ivan Pavlov, the Russian physiologist, famously trained dogs to associate the sound of a bell with food.
DAVID WELCH: We tend to have loud sound during happy times, so people get used to that association. If every time you have a party, if every time you meet your friends, every time you go out, there’s loud music playing, you start to sort of want the loud music in itself.
ALAN YU: He also says that the more people get used to hearing loud music, the more they go to clubs and concerts and come to expect it.
DAVID WELCH: At first, of course, really loud sound does seem unpleasant to most people, but once we adapt to it, we can tolerate it.
ALAN YU: But more people are becoming mindful of the potential damage loud music can do.
The musicians and venue employees I spoke to say more and more people are now wearing earplugs during shows. Shayna Kapilak and Benjamin Sher of Song People both noticed this.
SHAINA KAPELUCK: I just am more likely to see a jar of earplugs on the bar or see a jar of earplugs near the door where somebody is taking the door money. Like I just see earplugs more often at shows than I used to.
BENJAMIN SCHURR: There’s kind of a vibe or an aesthetic to like the earplugs you keep on your keychain. It’s kind of like a signal that not only do you care about your ears, but you go to shows.
ALAN YU: Earplugs are also better designed these days, says Anna Bixler. She’s an audiologist from Jefferson Health in Philadelphia.
She’s a big fan of concerts, especially electronic dance music. She says earplugs sound better now than they used to. Especially designed concert earplugs will make the music sound just as good, just not so loud.
ANNA BIXLER: And they look cool. The pair that I have, they actually have material in them that glows in the dark. So I will have people stop me and talk to me about it, which I love. I think any way to talk about it and get more people informed is really awesome, and show people it’s cool to protect your hearing.
ALAN YU: Another Philadelphia audiologist, Mary Kim from Penn Medicine, has also noticed the culture shift around earplugs.
MARY KIM: We just actually took my child over to meet the instrument night and tried to figure out next year, are we going to play a new instrument? And in the band room, there was a dispenser of hearing protection devices, which is not a thing that I saw growing up.
ALAN YU: She made sure to have earplugs available at her wedding.
MARY KIM: I actually gave them as my party favors. And we did not have a big band. We had a four or five-piece jazz band.
ALAN YU: She clarified that she did not give out the earplugs until the wedding ceremony and speeches were over.
Mary says she tells her patients to think of earplugs like sunscreen. You should keep them with you if you know you’re going to be exposed to dangerous levels of UV light, or in this case, sound.
MARY KIM: The one thing that I want to drive home is that these noise effects are permanent. They’re not reversible once they happen. At a certain point in our hearing changing in the inner ears, our ears essentially become like broken speakers. And even with volume that hearing aids can provide, our ears are not able to provide us with that clarity.
ALAN YU: Sean Svadlenak, the production manager at MilkBoy, puts it like this: You wear earplugs to protect your ears so you can listen to your favorite artists ,hopefully for many more years to come.
[MUSIC]
MAIKEN SCOTT, HOST: That story was reported by Alan Yu.
This is the Pulse. I’m Maiken Scott. We’re talking about noise and how living in a loud world affects our hearing and our health.
A lot of us listen to music, audiobooks, podcasts on our headphones — a personal bubble of entertainment. Or, we listen to stuff to block out other noises.
Over time, headphone listening can harm our hearing. In 2015, the World Health Organization released a study with the alarming finding that almost 50% of adolescents and young adults, 1.1 billion people globally, were at risk of hearing loss due to noise exposure in large part because of headphones. How much listening is safe?
Liz Tung looked into it.
LIZ TUNG, REPORTER: In 1998, Brian Fligor was a budding audiologist doing his clinical rotation at Boston City Hospital.
BRIAN FLIGOR: And there was a young man, a 15-year-old, who came into the clinic to get his hearing tested after he failed a school hearing screening.
LIZ TUNG: So Brian gets to work examining the kid. And right away, he sees what looks like the culprit, a massive plug of earwax in his right ear.
BRIAN FLIGOR: And so it was very obvious, like, oh, well, that’s why he didn’t pass. And the other ear was clear. So I sent him over to the nurses just for them to flush his ear.
LIZ TUNG: Afterwards, Brian decided to test the patient’s hearing again. As it turned out, the ear that had the plug of wax in it, his right ear, now had perfectly normal hearing. His left ear, though, the one without earwax —
BRIAN FLIGOR: Had a hearing loss that’s consistent with long-term noise exposure, resulting in a permanent hearing loss from noise.
LIZ TUNG: Brian was mystified. What he was seeing was the kind of hearing loss you’d expect in factory workers who’d spent years around noisy equipment. Or hunters who spent their weekends around the explosions of gunshots.
But this was a 15-year-old kid living in Boston. It had to be something else.
BRIAN FLIGOR: And so asking him, ‘Well, are you around a lot of high-level sound?’ He was like, ‘What do you mean?’ And I said, ‘Do you listen to music a lot?’ He was like, ‘Well, yeah.’ And I said, ‘How do you listen to it?’ He said, ‘On my headphones.’ ‘Do you have them with you?’ ‘Yeah.’ And he pulls it out.
LIZ TUNG: “It” being a Discman, which the kid used all the time to listen to rap. Remember, this was 1998, three years before the release of the iPod.
BRIAN FLIGOR: I said, ‘Well, how loud do you listen?’ And he said, ‘Well, not all the way up.’ And he showed me, and this is where it’s the old dial-style volume control. And it’s like a zero to 10. He had it between nine and 10.
LIZ TUNG: Light bulb moment. A disc man and headphones had caused the same level of hearing loss as years of work around dangerously loud machinery. And the only thing that had protected this kid, in his right ear, at least, was the plug of earwax that Brian had just removed.
BRIAN FLIGOR: And I said, ‘So that’s kind of high.’ He said, ‘All right, well, if that’s too loud, how loud can I listen?’
LIZ TUNG: Brian paused. It was a good question. One that he didn’t have the answer to. For people who spent hours listening to music on their headphones, how loud was too loud? So Brian decided to find out. In fact, he made that question the subject of his PhD dissertation.
To find an answer, he gathered together a bunch of CD players and a bunch of headphones, and he tested them to see how loud they got. He developed his own testing protocol and then compared his results with safety standards developed by OSHA, or the Occupational Safety and Health Administration, regarding safe noise levels in workplace settings.
Here’s what he found.
BRIAN FLIGOR: All of them had the capacity to be used at too high a level for too long a period of time, such that it would result in risk to someone developing a noise-induced hearing loss from using headphones.
LIZ TUNG: Now, danger levels are measured according to the noise dose level, a combination of how loud a sound is and how long you’re exposed to it. Brian’s results varied based on which CD player and headphones he was testing. But overall, he found it didn’t take much to exceed safe sound dose levels.
He finished with an official recommendation. If you’re using a Discman with headphones, you should be spending no more than one hour per day listening at 60% volume. Brian published his dissertation in a journal called Ear and Hearing in 2004. Six years after that 15-year-old boy first showed up in his office. And to Brian’s shock, his study blew up. Not only because Brian was one of the first to investigate this question, but because by then the phenomenon that was the iPod had been released, which meant that way more people than ever were now listening to music on the go. Of course, Brian’s study didn’t include the iPod, but that didn’t matter. It had captured the zeitgeist.
His study appeared in newspapers on the news. He was interviewed for a Rolling Stone article alongside Pete Townsend from The Who. Who blamed his own hearing loss not on his years of live performing, but rather on listening to studio recordings too loud on his headphones. And in 2005, Brian received his greatest honor, his study being featured on The Late Show with David Letterman.
[SOUND OF 2005 EPISODE OF LATE SHOW WITH DAVID LETTERMAN ]
DAVID LETTERMAN: Now listen to this. According to a new study, iPod headphones may cause hearing damage. Here now with some tips on how to protect your hearing.
LIZ TUNG: They bring out a respected audiologist who offers some safety tips on listening.
KENNETH SUTTON: To protect your hearing, only listen to music at 60% of the maximum volume. Limit iPod use to 30 minutes per day and consult a doctor if you experience any ringing.
LIZ TUNG: The punchline as he’s finishing up, fake blood spurting out of both of his ears.
DAVID LETTERAN: His ears are bleeding —
BRIAN FLIGOR: My joke as well, my career peaked like a year after I finished my PhD, because not me, but my work was being spoofed on Letterman.
LIZ TUNG: So the revolution started by the iPod had elevated Brian and his research to the national, even the global stage. In fact, the testing protocol had developed for a study, ended up being turned into international standards for how to test headphones. Brian says the study’s idea of measuring safety according to sound dosages, as opposed to just loudness, also gain traction.
[MUSIC]
LIZ TUNG: But with the iPod and the advent of streaming music in general, music files were getting processed and compressed in new ways, which had the effect of reducing the variation of volume levels in any given track.
BRIAN FLIGOR: Anything that is streamed, it is all almost exactly the same average level, because the range from the softest sound in the music to the loudest sound in the music is actually a really narrow window.
LIZ TUNG: You don’t get the kind of sudden spikes of loudness that you used to get with CD players.
BRIAN FLIGOR: It actually makes it really easy for us to measure the sound levels, because they’re all really similar.
LIZ TUNG: The good news is that devices and headphones today aren’t as dangerous as they were back in the 90s and before.
BRIAN FLIGOR: The CD players were louder than iPods, iPhones, or Android devices now. They’re actually quite a bit lower. They can be used for a lot longer, so the exposures can be pretty high. But the levels that they produce are not capable of causing an injury after, like, one really loud song you listen to. There would have to be something like a horrible malfunction of a device for it to result in actually like a sound exposure high enough to do damage.
LIZ TUNG: But that doesn’t mean they’re safe. Remember, it’s not just about volume. It’s also about dose, how long you’re listening to something. And hearing damage, just like sun damage to our skin, or the effects of smoking on our lungs, is cumulative.
BRIAN FLIGOR: So if we live long enough, we’re all going to develop hearing loss. The blood flow to our ears is actually not good enough to maintain really good hearing over our entire lifetime. That part of the body, the inner ear, is very greedy. It requires a lot of oxygen in order for it to work. It requires actually a lot of energy for it to do the job that it does. And because it’s so metabolically active, it produces a lot of waste product.
LIZ TUNG: And that waste product needs to be cleaned up. But if you’re exposing yourself to loud, if not deafening sounds —
BRIAN FLIGOR: Over time, the ear can be overworked. It can build up its waste product. And that waste product may not be cleared out as effectively as it needs to be. And that builds up, and it starts to kill off some of these very sensitive, very specialized hair cells. If those cells die, these specialized hair cells, if they die, they’re replaced along that membrane in our inner ear, the scar tissue. The scar tissue maintains the whole system, kind of keeps it all together. But it doesn’t contribute to this active process that is hearing.
And so because those hair cells don’t regenerate, they’re not replaced with another hair cell when they die, we lose incrementally hair cells as those are overworked. And so, lifetime wear and tear can be accelerated when the ear itself is overworked.
LIZ TUNG: In other words, it isn’t the sound itself that’s blowing out our hearing. It’s not like a big sound wave sweeps through and immediately destroys all our little hair cells. Rather, it’s the chemical reaction Brian just described that kills them off, accomplishing in some cases a lifetime’s worth of wear and tear in just a few months or years.
And this isn’t a rare thing that only happens to a small percentage of people. In fact, in 2022, a group of researchers working with the World Health Organization released a study looking at potential hearing loss among young people worldwide from two sources: loud concerts or events, and headphone use. And what they found was pretty staggering.
Here’s one of the authors, audiologist and epidemiologist Lauren Dillard.
LAUREN DILLARD: So we’ve showed that about a quarter of young people, 24%, are listening to personal listening devices at a risky level. And about half, or 48% were regularly attending loud entertainment venues. So we used these two estimates alongside the estimate of the global population of individuals aged 12 to 34 years to estimate that over one billion individuals could be at risk for hearing loss from loud sound exposure.
LIZ TUNG: And this wasn’t the first time researchers reached that number either. A previous analysis in 2015 by the World Health Organization had come to the same conclusion, which is part of what led the WHO to launch a hearing safety initiative designed to answer that same question that Brian’s 15-year-old patient had posed years before. How loud is too loud?
Lauren told me that in her study, they judged too loud based on global recommendations of occupational noise exposure limits, which in this case was 80 decibels for 8 hours a day, 40 hours a week. About as loud as a garbage disposal or a busy street.
Now it’s very difficult for laypeople to measure exactly how many decibels are coming out of their headphones. But in 2019, the World Health Organization released international standards for audio device manufacturers in an effort to standardize safe listening. Standards they developed with help and input from industry players.
A few examples? Volume control systems that are more easily accessible and easier to configure. Parental control systems. And headphone safety mode, which reduces the volume once you start hitting the danger zone. And just recently, they also released new standards for gaming that include similar measures. Messages to let gamers know when the volume is too loud, or they’re hitting their maximum safe dosage of sound.
And that’s just the beginning. Brian says some people may have noticed that they already get notifications on their phones when they’re listening to something too loud. But upcoming safety features based on WHO standards should be getting dropped any day now by major manufacturers.
BRIAN FLIGOR: What we can do is look for information that’s coming from our phone. It’s going to be released in new operating system updates that says, hey, you’ve used up about 20% of your total noise dose for today. You’ve got this many more hours you can listen if you continue listening this way.
[MUSIC]
MAIKEN SCOTT, HOST: That story was reported by Liz Tung.
I checked in with Rick Nietzel, the noise exposure researcher at the University of Michigan, to see if he has any advice when it comes to choosing headphones.
RICK NIETZEL: One of the sort of tips I’d love to leave your listeners with is the fact that earbuds or headphones that are designed and marketed as having sound blocking or noise isolating characteristics, those are always the better choice.
And it’s for this reason, if you imagine yourself riding on a subway or a loud train or an airplane, if your earbuds or headphones are very leaky, in other words, they don’t really block out a lot of the sound around you, you’re going to end up having to turn the volume up pretty dramatically to listen to your music or your podcast or whatever, just to overcome that ambient sound. Whereas if you’re using one of those over the ear headphones or an earbud that actually seals up your ear canal, in doing so, that’s going to block out that background sound and it’s going to allow you to listen to the same media, again, podcast, music, movie, whatever, but you’re going to be able to listen at a lower level.
MAIKEN SCOTT: Rick is heading a research study that’s going to give us a much better picture of noise exposure in the US.
In 2019, he and his team at the University of Michigan launched the Apple Hearing Study in partnership with the tech company. Using Apple Watches or iPhones, participants opt in to have an app measure the amount of noise they’re exposed to.
INTERVIEW:
RICK NIETZEL: We’ve been following over 180,000 people who have volunteered to be in the study and chosen to share noise levels, both from their environment, if they have an Apple Watch, and also from their headphone use.
We figured out, hey, we could do essentially a groundbreaking study here where we could scale up and have potentially hundreds of thousands of participants and get really high resolution data, not only on how much noise exposure people have from their environment, from their workplace, at home while they’re sleeping, but also use that same app to test people’s hearing. So again, really for the first time at scale, we could try to answer the question, well, what’s happening in America in terms of noise levels? Are we getting quieter or are we getting louder as a country? We really haven’t had the data to answer that, but also asking what’s happening to Americans’ hearing over time.
MAIKEN SCOTT: And how is the noise data itself being collected?
RICK NIETZEL: So our participants in the Apple Hearing Study can share two different types of noise data. One, for the participants who have an Apple Watch, which turns out to be the majority of our study participants, the Watch has a noise app on it that can, with their permission, share with us the sound levels that are happening in their workplace, when they’re out shopping, going to a concert, whatever they’re doing.
And then every iPhone has built into it now, essentially, the ability to measure how much sound people are being exposed to through headphones or earbuds as they consume media on their iPhones. So they might be watching a movie, they might be watching YouTube, they might be listening to a podcast, or otherwise listening to music. And again, when they choose to share those data with us, we can get that information and know over any, for instance, 24-hour period, all the way up to the many years that some of our participants have been in the study, we can know how much noise they were exposed to and when and how those exposures were happening.
MAIKEN SCOTT: And that’s pretty genius if you think about what researchers must have gone through in the 70s to collect that kind of data before, right? I mean, you had to, back then, walk around with recorders and measure stuff. There was no way you could have ever collected this kind of real-time information.
RICK NIETZEL: Absolutely not. I will share that even when I was doing my training in the late 1990s and early 2000s, there were devices available that could provide essentially the same information about people’s environmental sound. They’re called noise dosimeters. They were about the size of a brick and about the weight of a brick. You would wear them around, not exactly a comfortable experience. Back in the 70s, there were some very early studies done on school children, and they said, ‘Hey, we want this nine-year-old to wear like a 20-pound backpack with equipment that will measure sound.’ Not surprisingly, they didn’t get a lot of participants.
Whereas today, people are already wearing their Apple Watch for other reasons. Many folks have a smartphone on them all the time. And so being able to tap into that in a very non-invasive way, not change people’s behavior by asking them to wear a 20-pound backpack, that’s been a real game changer.
And the other thing that has been, I would say, pretty groundbreaking is the fact that we’re able to, through this Apple Hearing study, collect information about people’s headphone or earbud exposure. Previously, that was simply impossible to do at any large scale. So now, to have nearly 200,000 folks who are sharing with us data collected and given to us with permission through their headphones, we’re really starting to get, for the first time, a sense nationally of, well, how does headphone noise stack up compared to environmental noise?
MAIKEN SCOTT: And what are some of the big, interesting findings that have come out of this so far?
RICK NIETZEL: So noise exposure turns out to be pretty darn common. So between one in three and one in four Americans exposed to environmental sounds that might put them at risk of hearing loss, between, say, one in five and one in six people exposed to enough headphone sound that might put them at hearing loss, we’ve found that something like one out of six of our participants are experiencing tinnitus or tinnitus, which is ringing or whistling or buzzing in their ears. They’re experiencing that on a daily basis.
We’ve discovered, for instance, that there appear to be important differences in noise exposure by things like race and ethnicity. So our Black and Hispanic participants tend to have some of the highest exposures to noise of anyone in our study, which has led us to ask questions like, well, are they working in jobs or living in neighborhoods that are excessively exposed to sound?
We’ve discovered, somewhat to our surprise, that there don’t seem to be any differences in exposure between males and females in our study. On the other hand, there are very strong differences in terms of age. So we’ve found that our youngest participants have the very highest exposures. And then those exposures steadily come down as we increase in age group up until our group of oldest participants who are 65 years and over.
We have also found, for instance, that about 40% of our participants have reported that they perceive some issues with their hearing, but that about three and four of our participants haven’t had their hearing tested in the last 10 years outside of our study. So all of these things are starting to give us a better picture of how much exposure is happening.
We also have some limited geographic information on these folks. We’ve seen that not every state has similar exposures. Some are much louder than others. Surprisingly, we’ve seen that exposures among our participants who live in rural areas are, in many cases, just as high as those who live in urban areas. We initially thought that folks who live in big cities were likely to have the most noise exposure, but that hasn’t really borne out. And again, we’re starting to see that while noise is a ubiquitous exposure, people don’t necessarily or haven’t necessarily been accessing hearing health care in the way that they might other types of health care.
MAIKEN SCOTT: Yeah, I was trying to think about the last time I had my hearing checked, and I think it’s only been maybe once in my lifetime.
RICK NIETZEL: Right.
MAIKEN SCOTT: I mean, it’s not part of routine care, and I don’t remember any health professional ever asking me, like, ‘Do you have trouble hearing?’
RICK NIETZEL: Yeah, it’s true. I have had many colleagues in the field of hearing loss prevention say, you know, wouldn’t it be great if just like when you go to the dentist and get your teeth checked and they hand you a toothbrush, wouldn’t it be great if when you went to the doctor, they handed you a pair of earplugs and said, ‘Hey, you know, consider taking care of your hearing.’
Unfortunately, that’s not really a part of our health care approach right now, but I think it’s a moment where we have a great opportunity to think about emphasizing the importance of hearing to folks and the importance of noise. As I said, it’s not just about hearing; it’s about cardiovascular health and mental health, and there are lots of benefits from living a less noisy lifestyle.
MAIKEN SCOTT: Rick Nietzel is a professor of environmental health sciences at the University of Michigan and the principal investigator of the Apple Hearing Study.
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MAIKEN SCOTT, HOST: This is the Pulse. I’m Maiken Scott. We’re talking about noise and how it affects our hearing and our health.
Hearing loss is kind of sneaky because, usually, it happens little by little over time.
MEG WALLHAGEN: Especially with age-related hearing loss, it comes on slowly.
MAIKEN SCOTT: That’s Meg Wallhagen, a geriatric nurse practitioner and professor of nursing at the University of California, San Francisco.
MEG WALLHAGEN: So individuals are not even as aware — they sort of adapt to it. They don’t realize they’re not hearing. And they’ll say, ‘Gee, can you repeat that?’ Or, ‘What did you say?’ And don’t think much about it. And it just keeps getting worse. So the person is adapting to it before it really becomes an issue.
MAIKEN SCOTT: Meg has spent decades researching hearing loss. Hearing aids are expensive and not usually covered by insurance. That gets in the way of people seeking treatment.
But Meg says there’s another major factor: Stigma around hearing loss and wearing hearing aids.
MEG WALLHAGEN: People associate or have associated hearing loss with aging and other kinds of problems related to aging. So there’s a confound, if you will, between concerns around aging and issues around showing disability, not being able to hear. So hearing aids are more of a marker of that disability.
INTERVIEW:
MAIKEN SCOTT: I mean, one of the questions is to me, when you look at a hearing aid, it’s small, it’s barely visible, it’s tucked behind a person’s ear. It’s really no big deal, and we don’t make a big deal out of people wearing glasses. So, how come our thinking on this hasn’t changed?
MEG WALLHAGEN: It’s a really good question. I think one of the issues, of course, is that it’s true that hearing aids have become increasingly small. And it’s amazing how very powerful these very tiny little pieces of technology are, given what they’re dealing with.
I think the issue in terms of, they used to be more visible, and I don’t think it’s been helpful for the ads to say almost invisible, nobody can see it, because that sort of implies nobody should see it. So it adds to the stigma of a hearing aid. And everyone wants then for their hearing aid to be invisible when in truth the person should get the hearing aid that best manages their specific kind of hearing loss.
But in terms of the comparison to glasses, it’s really not totally a fair comparison, because usually when we think about a comparison to glasses, we’re comparing them to reading glasses. That’s for correcting something that’s correctable, that’s really correctable. When you put your glasses on, you really do see. But with hearing aids, you can’t cure hearing loss. With hearing loss, you’re looking at something that has changed the inner ears.
MAIKEN SCOTT: Meg says the most common type with aging is the loss of high frequencies.
MEG WALLHAGEN: And so what we’re hearing is we hear the vowels more than the consonants, because consonants are high frequency and vowels tend to be more low frequency.
MAIKEN SCOTT: It’s like a crossword puzzle where all of the vowels are filled in, but the consonants are missing. And people might say, I can hear you, but you’re mumbling.
MEG WALLHAGEN: And so with loss of the high frequencies, we’re only hearing parts of the words, and we can’t make sense of it. Our brain tries to fill in, which is why we make mistakes often when someone says something, and you’re responding to what you heard. But what you heard wasn’t what they said.
MAIKEN SCOTT: Hearing aids can’t restore what’s lost, but they can amplify the frequencies that people are having a hard time with. And sometimes if people leave hearing loss unaddressed for quite some time and then they start to wear hearing aids, it seems like it’s harder to adjust to those hearing aids than, right?
MEG WALLHAGEN: Yeah, it tends to be because the way we hear it’s really not in our ears. It’s in our brain. But the ear has to send appropriate signals to the brain for us to make sense of it. Well, if the brain doesn’t get that stimulation, those neurons often change.
So when you start to use hearing aids, you do have to relearn how to listen. Your brain has to get used to those noises. You haven’t heard them for a while. So you hear things that sometimes sound too loud because it’s just you haven’t heard it for a long time.
MAIKEN SCOTT: Meg says over time, unaddressed hearing loss can also lead to isolation and even loss of cognitive function. She and other researchers are introducing programs that encourage hearing screenings in primary care settings.
Meg Wallhagen is a geriatric nurse practitioner and a professor of nursing at the University of California, San Francisco.
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MAIKEN SCOTT, HOST: That’s our show for this week. The Pulse is a production of WHYY in Philadelphia. You can find us wherever you get your podcasts.
Our health and science reporters are Alan Yu and Liz Tung. Charlie Kaier is our engineer. Our producers are Nichole Currie and Lindsay Lazarski. I’m Maiken Scott. Thank you for listening.
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Behavioral Health Reporting on the Pulse is supported by the Thomas Scattergood Behavioral Health Foundation, an organization that is committed to thinking, doing and supporting innovative approaches in integrated healthcare.
WHYY’s Health and Science Reporting is supported by a generous grant from the Public Health Management Corporation’s Public Health Fund. PHMC gladly supports WHYYand its commitment to the production of services that improve our quality of life.
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