WHYY-FM’s “The Pulse” program featured an episode about noise and health in August 2025. You can listen to it as a stream or as a downloadable podcast on several services — or read a text transcript below.
MAIKEN SCOTT (host): This is The Pulse — stories about the people and places at the heart of health and science. … 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.
Prof. RICK NIETZEL (professor of environmental-health sciences): 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: Rick Nietzel 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.
Prof. 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.
Prof. RICK NIETZEL: Noise exposure 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. [And] 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 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 it has an immediate impact on our hearing where we’re like, “Whoa, my ears are ringing or I’m having trouble hearing.“ But usually the effect accumulates over time.
Prof. 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 happening in most cases because it happens over the course of months, years, or even decades. And the rate is slow enough, and the change is subtle enough, that people simply don’t realize until maybe decades later, when people ask, “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?”
[But] 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 that, honestly, 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?
Prof. RICK NIETZEL: There are a couple of sort of prevailing theories. 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.
[And] it turns out that workers who are exposed to loud noise during their work 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, that’s not a bad thing occasionally, but if your body is constantly in that excited state 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?
Prof. RICK NIETZEL: We actually have a fair amount of data that allow us to determine what a “safe” level of noise exposure is [to avoid hearing loss]. 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 — this is not an extreme level. 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.
That doesn’t mean you can’t go above 70 decibels (dB). For instance, if you’re out mowing the lawn with a gas-powered lawnmower, that might be 90 dB. If you’re operating a chainsaw, that could be 100 or 105 dB. Certainly, gunshots can be upwards of 130 or 140 dB. 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 dB.
Now, the higher people get above 70 dB on average, the greater their risk of hearing loss. So all of this is to say it’s actually [not a risk] 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?
Prof. RICK NIETZEL: There’s actually two different ways that high noise can harm hearing. One is pretty uncommon: what is called “acoustic trauma.” This is when noise is excessively loud — 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. 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. If those same little hair cells that reside in your inner ear — each of which is listening for a specific frequency of sound — are exposed to excessive amounts of sound over chronic periods or long periods of time, they can suffer metabolic damage and slowly wither away. And unfortunately, once they’ve been damaged enough, they will not recover.
So that’s why I say, for most folks, the risk of hearing loss is not going to happen today from a single event, but rather it results from chronic exposure over months, years, or even decades — the sort of slow, insidious damage to those inner hair cells.
MAIKEN SCOTT: OK, 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 of shows in small venues that were really loud, that probably could do some damage over time.
Prof. RICK NIETZEL: 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, [whether it’s toxic] chemicals or noise, is that it’s not just about how loud it is, it’s also how long the exposure is, and also how frequently you have [such] exposures.
So an occasional concert is going to be fine for the vast majority of people. Many of us, myself included, have probably gone to a show … and maybe experienced a sensation after the concert that their hearing was muffled, or it sounded like they were underwater, or had a sense of fullness in their ears. That’s really our body’s only way of telling us, “That was too much sound.“ You’ve essentially temporarily damaged your ability to hear, and it will typically recover within 24 hours or so.
MAIKEN SCOTT: Yeah, but it definitely is that feeling like, “Don’t do that again, please.”
Prof. RICK NIETZEL: Absolutely.
MAIKEN SCOTT: Now let’s take a closer look at live music and how it affects our hearing. 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 (WHYY 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.
ANNA REED (general manager of the Philadelphia music venue Milkboy): There was a time before, when I was 18 and 19, I don’t think I cared about [excessive sound levels] all that much. I was like, the louder the better.
TARIK SHAPLI (guitarist for the band Tone Bandits): Nobody wore earplugs back then. My first concert was Black Sabbath. My second one was Led Zeppelin — big loud shows, and nobody ever thought about it. It just wasn’t a thing.
DRAKE TYLER (drummer for the band Song People): You could come up with various reasons why you wouldn’t want to look like you were putting on a bunch of safety gear to go to a show or whatever.
ALAN YU: Everyone told me that in one way or another how, after years of going to shows blissfully unaware of how dangerously loud the volume can be, they started to notice the impact.
ANNA REID: Being at a show every single night, I kind of started to realize, like, “Oh, this is constant exposure to high levels of sound. I should probably protect my ears.”
SEAN SVADLENAK (production manager at Milkboy venue): I got tired of coming home from a loud show with ringing in my ears and now knowing that little cilia in my ear are never going to work again.
BENJAMIN SCHURR (bass guitarist for Song People): I used to live in D.C., and there was 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 played this crushingly loud set. And I was like, “Oh, I’ll just put some toilet paper in my ears.“ And I 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 [when you wear them]. Milkboy often puts on several shows a week. Sean Svadlenak 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.
ALAN YU: Production managers do sound checks before concerts to get the mix right. Johnny Brenda’s is an independent music venue in Philadelphia. It fits around 250 people. Singer Shaina Kapeluck from the band Song People goes on stage [before shows] to test the volume level. She sings with the band’s two guitarists and a drummer playing at the same time. Sound engineer Jeff Sarafinas runs the sound board, and adjusts their [respective volume] levels.
JEFF SARAFINAS (sound engineer): [It‘s] definitely an indie rock band, but with an intentionally quieter vocal. That kind of things happens a lot, and sounds awesome on a recording. And it can sound awesome live, too — they just need more [amplification of the] vocals on stage, because the instruments themselves are loud and then it’s a quieter vocal. So I just had to turn that up.
ALAN YU: So there are logistical reasons why live concerts are loud. But concert-goers also tend to like loud music. MilkBoy‘s 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 at the University of Auckland in New Zealand, looked into why people like music that they either know or suspect is too loud to be healthy for them. 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.
Prof. 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, 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.
Prof. 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 near the door where somebody is taking the door money. I see earplugs more often at shows than I used to.
BENJAMIN SCHURR: There’s kind of a vibe or an aesthetic to 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, 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, but not as 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 actually just took my child over to “meet the instrument” night to try to figure out if we’re going to play a new instrument next year. 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: Mary also 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 for many more years to come.
MAIKEN SCOTT, host: 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 that 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? Reporter 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 out 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 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 I asked him, “Are you around a lot of high-level sound?” And he said, “What do you mean?“ So I said, “Do you listen to music a lot?” He said yes. “How do you listen to it?” I asked. “On my headphones,” he said. So I asked, “Do you have them with you?” And he pulled them out.
LIZ TUNG: It was 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, “How loud do you listen?” He said, “Not all the way up,” and showed me the old dial-style [rotating] volume control that goes from zero to 10. He had it between nine and 10.
LIZ TUNG: It’s a “lightbulb moment” — a Discman 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, “That’s kind of high.” He said, “Well, if that’s too loud, how loud can I listen?”
LIZ TUNG: Brian paused. It was a good question, and 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 (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 volume level for too long a period of time, such that it would result in the risk of someone developing a noise-induced hearing loss from using headphones.
LIZ TUNG: Sound danger-levels are measured according to the noise dose — 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 he was one of the first to investigate this question, but because by then 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 and 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.
DAVID LETTERMAN [recording]: “Now listen to this. According to a new study, iPod headphones may cause hearing damage. Here now [are] some tips on how to protect your hearing.”
LIZ TUNG: They brought out a respected audiologist who offers some safety tips on listening.
KENNETH SUTTON (audiologist on Letterman): “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 was that, as he’s finishing up, fake blood spurted out of both of his ears.
DAVID LETTERMAN: “His ears are bleeding!”
BRIAN FLIGOR: My joke as well [was that] my career peaked a year after I finished my PhD, not because of me, but my work was being spoofed on Letterman.
LIZ TUNG: The revolution started by the iPod elevated Brian and his research to the national, even global, stage. And the testing protocol he developed for the study ended up being turned into an international standard for how to test headphones. Brian says the study’s idea of measuring safety according to sound dosages, as opposed to just loudness, also gained traction.
But with the advent of the iPod and music streaming in general, music files were getting processed and compressed in new ways, which had the effect of reducing the variation in volume levels within any given track.
BRIAN FLIGOR: Anything that is streamed is all almost exactly the same average volume level, because the range from the softest sound to the loudest sound in [compressed] 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: CD players were louder than iPods, iPhones, or Android devices now, [which] are actually quite a bit lower, and can be used for a lot longer — so the exposures can [still] be pretty high. But the levels that they produce are not capable of causing an injury [from] one really loud song you listen to. There would have to be a horrible malfunction in a device for it to result in a sound exposure high enough to actually 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 actually requires 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 specialized hair cells die, they’re replaced along that membrane in our inner ear [with] scar tissue. The scar tissue maintains the whole system, kind of keeps it all together, but doesn’t contribute to the active process that is hearing.
And because those hair cells don’t regenerate — they’re not replaced with another hair cell when they die — we lose hair cells incrementally as they’re are overworked. 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 a big sound wave that sweeps through [our ears] and immediately destroys all our little hair cells. Rather, it’s the chemical reaction that kills them off, in some cases accomplishing 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. Audiologist and epidemiologist Lauren Dillard was one of the authors.
LAUREN DILLARD (audiologist / epidemiologist): We’ve shown that about a quarter (24%) of young people are listening to personal listening devices at a risky level. And about half (48%) are regularly attending loud entertainment venues. So we used these two estimates, along with the estimated global population of individuals from ages 12–34, to estimate that over one billion individuals could be at risk for hearing loss from loud sound exposure.
LIZ TUNG: This wasn’t the first time researchers reached that number either. A previous analysis by the World Health Organization in 2015 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 Fligor’s 15-year-old patient had posed years before — how loud is too loud?
In Lauren Dillard’s 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 people 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. 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. 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 [incorporated] by major manufacturers any day now.
BRIAN FLIGOR: We can look for information that’s coming from new phone operating-system updates that will say, “You’ve used up about 20% of your total noise-dose for today. You’ve got X more hours that you can listen [safely] if you continue listening this [loud].”
MAIKEN SCOTT (host): Rick Nietzel, the noise-exposure researcher at the University of Michigan, has advice when it comes to choosing headphones.
Prof. RICK NIETZEL: Earbuds or headphones designed and marketed as having sound-blocking or noise-isolating characteristics are always the better choice. If you’re riding on a loud subway, train, or airplane, and your earbuds or headphones are very “leaky” — they don’t 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 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, that’s going to block out that background sound and allow you to listen to the same podcast, music, movie, whatever, at a lower level.
MAIKEN SCOTT: Rick is leading a research study that’s going to give us a much better picture of noise exposure in the U.S. In 2019, he and his team at the University of Michigan launched a hearing study in partnership with the tech company Apple. Using Apple Watches or iPhones, participants opt in to have an app measure the amount of noise they’re exposed to.
Prof. RICK NIETZEL: We’ve been [collecting data from] 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 [if they use their iPhone to listen to music].
We figured out that we could do a groundbreaking study where we could … 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 — their workplace, at home while they’re sleeping, [etc] — but also use that same app to test people’s hearing.
So really for the first time [on a large] scale, we could try to answer the question [of] 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 [or] … what’s happening to Americans’ hearing over time.
MAIKEN SCOTT: And how is the noise data itself being collected?
Prof. RICK NIETZEL: 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 … 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 every iPhone now has built into it 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’re watching a movie or YouTube, or listening to a podcast or music, we can get that information and know … how much noise they were exposed to, when, and how those exposures were happening.
MAIKEN SCOTT: 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? Back then, you had to walk around with recorders and measure sound. There was no way you could have ever collected this kind of real-time information.
Prof. RICK NIETZEL: Absolutely not. Back in the ’70s, there were some very early studies done on school children, and they said, “We want this nine-year-old to wear a 20-pound backpack with equipment that will measure sound.” Not surprisingly, they didn’t get a lot of participants. 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 and weight of a brick. You would wear them around, [which was] not exactly a comfortable experience.
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, has been a real game changer.
And the other thing that has been pretty groundbreaking is that we’re able to … 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 through their headphones, we’re really starting to get for the first time a sense of how does headphone noise stack up compared to environmental noise nationally?
MAIKEN SCOTT: What are some of the big, interesting findings that have come out of this so far?
Prof. RICK NIETZEL: Noise exposure turns out to be pretty darn common. Between one in three and one in four Americans are exposed to environmental [ambient] sound levels that might put them at risk for hearing loss. Between one in five and one in six people are exposed to headphone sound levels that might [cause] hearing loss. And we’ve found something like one out of six of our participants are experiencing tinnitus, which is ringing / whistling / buzzing in their ears on a daily basis.
We’ve discovered that there appear to be important differences in noise exposure by things like race and ethnicity. 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, 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: We’ve found that our youngest participants have the very highest exposures. And those exposures steadily come down as we increase in age group, up until our oldest participants who are 65 years and over.
We have also found that about 40% of our participants have reported that they perceive some issues with their hearing, but that about three out of 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: We’ve seen that not every state has similar exposures — some are much louder than others. Surprisingly, we’ve seen that exposures among 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 [although] noise is a ubiquitous exposure, people haven’t necessarily been accessing hearing healthcare in the way that they might other types of healthcare.
MAIKEN SCOTT: 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.
Prof. RICK NIETZEL: Right.
MAIKEN SCOTT: It’s not part of routine care, and I don’t remember any health professional ever asking me, “Do you have trouble hearing?”
Prof. RICK NIETZEL: It’s true. I have had many colleagues in the field of hearing-loss prevention say, “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, when you went to the doctor they handed you a pair of earplugs and said, ‘Consider taking care of your hearing’.”
Unfortunately, that’s not really a part of our healthcare approach right now, but we have a great opportunity to think about emphasizing the importance of hearing and noise. As I said, it’s not just about hearing — it’s about cardiovascular and mental health, and there are lots of benefits from living a less noisy lifestyle.
MAIKEN SCOTT: This is The Pulse. 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.
Prof. MEG WALLHAGEN (professor of nursing, Univ. of California / San Francisco): Especially with age-related hearing loss, it comes on slowly. 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, ‘Can you repeat that?’ Or, ‘What did you say?’ But 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 she says there’s another major factor: Stigma around hearing loss and wearing hearing aids.
Prof. MEG WALLHAGEN: People associate or have associated hearing loss with aging and other kinds of problems related to aging. So there’s a [conflict] between concerns around aging, and issues around showing disability (not being able to hear). And hearing aids are more of a marker of that disability.
MAIKEN SCOTT: 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?
Prof. MEG WALLHAGEN: It’s a really good question. It’s true that hearing aids have become increasingly small. And it’s amazing how powerful these very tiny little pieces of technology are, given what they’re dealing with. They used to be more visible, but I don’t think it’s been helpful for ads to say [they‘re] “almost invisible, nobody can see it,” because that sort of implies nobody should see it. It adds to the stigma of a hearing aid. And then everyone wants their hearing aid to be invisible when in fact people 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 a totally fair comparison, because usually we’re comparing them to reading glasses. That’s for correcting something that’s actually 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 [trying to address] something that has changed people‘s inner ears.
MAIKEN SCOTT: The most common type [of hearing loss] with aging is the loss of high frequencies.
Prof. MEG WALLHAGEN: And so 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.
Prof. MEG WALLHAGEN: With the 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 [that] 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 a long time and then they start to wear hearing aids, it seems like it’s harder to adjust to those hearing aids than, right?
Prof. MEG WALLHAGEN: It tends to be, because the way we hear is really not in our ears — it’s in our brains. But the ear has to send appropriate signals to the brain for us to make sense of it, and if the brain doesn’t get that stimulation [due to hearing loss], those sound-sensing neurons often change.
So when you start to use a hearing aid, you have to re-learn 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.