Can we save the quietest places in the world?

Our planet’s rich nature sounds are disappearing, drowned out by human-made noise.

Sound recordist Matt Mikkelsen travels the world, listening to and working to preserve our vanishing soundscapes.

Today, On Point: Can we save the quietest places in the world?

Matt Mikkelsen, field recordist and sound engineer with Quiet Parks International. Executive director of Wilderness Quiet Parks. He observes, records, researches and works to preserve natural soundscapes.

Erica Walker, assistant professor of epidemiology at the Brown University School of Public Health, where she also runs The Community Noise Lab.

Paul Anderson, director of the Coral Reef Aquarium Fisheries Campaign and fisheries biologist.

Steve Orfield, runs the multisensory design research lab at Orfield Laboratories in Minneapolis, Minnesota. The lab’s anechoic chamber is globally recognized as the quietest room in the world.

Part I

MEGHNA CHAKRABARTI: Today, we're going to try a little slow journalism. An entirely different pace of being. So I invite you to join us in some close and deep listening.

Matt Mikkelsen joins us today, and Matt, what are we listening to right now?

MATT MIKKELSEN: Hi, Meghna. This is a recording I lovingly call Popcorn Frogs, and this is recorded in the Ecuadorian Amazon jungle on the Zabalo River.

CHAKRABARTI: The Zabalo River. So tell us more about it. What does it look like in the place that you recorded this?

MIKKELSEN: Being from rural New Jersey, the Ecuadorian Amazon is about as different as it gets, I'd say, from what I grew up with and what I was used to. The Amazon is this place that we hear about a lot as people, and going there for the first time was still unlike anything I could have imagined.

The rivers are huge and wide and there's lots of silt in the water. And you just see this concentration of life that is really hard to imagine.

CHAKRABARTI: Let's listen to it just a little bit more of this in the clear for a second.

(NATURAL SOUNDS)

CHAKRABARTI: So the popcorn frogs there, but can you identify some of the other things that we're hearing?

MIKKELSEN: One of the really incredible things I've found about tropical jungles in general, but especially the Amazon, is the number of different insect and frog species that are making sound at any given time. I'm no entomologist, I'm not super great at identifying specific species, but in this recording, you can probably hear 10 to 15 different insects and frogs, all vocalizing at the same time, but they all have their like frequency lane. They're all keeping to themselves and they're all audible. And they've evolved that way over time. So they all have clear communication. It's really incredible.

CHAKRABARTI: Oh, that's so interesting. Frequency lanes. Okay. But the interesting thing though, is that you actually, no, let me have you tell the story.

Why were you there to record the sounds on the Zabalo River in Ecuador?

MIKKELSEN: (LAUGHS) That's a question I ask myself frequently.

CHAKRABARTI: (LAUGHS)

MIKKELSEN: I have a really interesting job where I travel around the world and record the sounds of nature. That work is twofold. Part of it is that how I make a living is I record these sounds and I edit them and I sell them as sound libraries to sound designers and radio producers and people who make video games, to incorporate into their movies and their products and things like that.

But kind of the heart of the work lies in this idea that we're losing the ability to listen to nature without noise pollution. The number of places, wild places that we have left in the world that are mostly free from noise pollution, are dwindling at a rapid rate. So a lot of my work has to do with trying to find these places and take data on them and then work to protect them.

CHAKRABARTI: So a little bit more here of the Zabalo River.

(NATURAL SOUNDS)

CHAKRABARTI: It's such a symphony. It's such a symphony of natural sounds, which is beautiful and fascinating, because this was a place that you visited that was awarded as a Wilderness Quiet Park in 2019. The first place given that award, of a Wilderness Quiet Park. So this idea of quiet spaces doesn't mean a total absence of sound, right?

It's a total absence of human generated noise, Matt.

MIKKELSEN: Absolutely. I along with a few other really incredible folks helped to start a nonprofit called Quiet Parks International, where we look to find places like the Zabalo River that are mostly free from noise pollution. So we can listen to nature without noise pollution.

And yeah, the Zabalo River was the first place given the Wilderness Quiet Park Award. My title at the organization is the director of Wilderness Quiet Park. So that's my lane, as I look at wilderness areas, I take data on them and try and analyze how much noise pollution is in a park.

And if the park meets our kind of criteria, we worked with local land managers and the local community there to try and recognize and then steward this resource of the soundscape. And looking at soundscapes as a resource, not a new field of study but it's relatively niche and evolving very rapidly.

CHAKRABARTI: Before we move further, I want to apologize to all Ecuadorians out there because I have been mispronouncing the name of this region. It's Zabalo, as you said. I was saying Zabalo. I have a weird habit of emphasizing the middle syllable of words. That's how you know this is live, Matt. Tell me a little bit more about the Quiet Parks International and your work specifically with the wilderness quiet parks. Because this idea that quiet places are endangered, not just in cities, obviously, but around the world, is a really interesting one. What's the purpose or the need for the preservation of quiet places?

MIKKELSEN: It's a really great question because thinking about sound as a resource takes a little bit of mental gymnastics at first. But as you can hear in that recording of all those frogs and all those insects, all species evolved to communicate with certain frequencies. And that communication is really important for species.

So whether you're talking about birds, you're talking about mammals, nature is busy communicating all the time. And it's important that they can communicate to accomplish stuff like not getting eaten by predators and finding mates and protecting their offspring and finding shelter, all these things. So when noise pollution enters an area, what it does is it hinders nature's ability to communicate in that way. So ecologically sound is important for nature.

It's also a really great indicator of the overall health of ecosystems. In places where we see less noise pollution, we also see less air pollution and less water pollution and more intact ecosystems, for the most part. And then also from a human standpoint, looking at it very human eccentrically, quiet is important for us.

And like you mentioned, Meghna. Quiet, when I say quiet, I'm not talking about a lack of sound overall. I'm talking about a lack of noise pollution. So places like the Amazon jungle are quiet when it comes to noise pollution, but they're loud and cacophonous. And it's a beautiful symphony of sound, like you said.

But for us as humans, to be able to truly be present and enjoy nature and enjoy being present, quiet is a really important aspect of that. And we really believe that when we can experience quiet spaces, we can feel that quiet on the inside, and it helps us be happier and healthier people.

CHAKRABARTI: We'll talk more about that later, about the impacts on all life, including human life, of excessive noise, because it makes total sense, Matt.

Because we, as human beings, we evolved into that state of nature, right? The kinds of excessive noise that we're talking about, human made excessive noise, are relatively recent. Very recent in evolutionary history. So our bodies are built for a different kind of sonic environment. But you sent us some wonderful recordings of different quiet places that you've been to and have either worked with people there or are trying to preserve. So I want to hear, I love the fact that this is about sound. I want to, let's do some more deep listening to some of these places. In the United States, as far as I understand, the Boundary Waters Canoe Area Wilderness in Minnesota is one of the two places in the U.S. that have been awarded a Wilderness Quiet Parks Award. So let's listen to a recording you made there in the Boundary Waters Canoe Area.

(NATURAL SOUND)

CHAKRABARTI: Loons, Matt.

MIKKELSEN: I love that recording.

CHAKRABARTI: Oh my gosh, it's amazing. They're so loud. But not in a harsh way.

MIKKELSEN: It's like one of the most beautiful sounds I think that you can experience as a human. And maybe I'm partial because I live in northern Minnesota and I'm actually going back to the Boundary Waters tomorrow on a trip.

But it's just, it's this sound that provides so much awe and wonder if you've never listened to loons before. Here you go. So that's at the Boundary Waters Canoe Area. The other place in the U.S. that has been designated, or let me say awarded, a Wilderness Quiet Park Award is Glacier National Park.

So here's some of Glacier National Park, some sounds recorded by one of your colleagues.

(NATURAL SOUNDS)

CHAKRABARTI: Matt, do you know where in Glacier that was recorded?

MIKKELSEN: Yes that recording was taken in the northwest region of Glacier National Park. It's important to note that with all of these wilderness quiet parks and the quiet places in general, it's not like the whole national park is going to have that quiet that we're talking about.

It's very specific points that we spend a lot of time trying to find. Because Glacier National Park can be very noisy at times if you've ever been, on Going-to-the-Sun-Road or something like that. But yeah, so  that's on one of the lakes in kind of the Northwest region recorded by a good friend and colleague, Nick McMahon.

CHAKRABARTI: I see. We have to take a break in just about a minute, in 30 seconds here, but can you give me the quick definition of how ... the award is made for a quiet, a wilderness quiet park.

MIKKELSEN: So we have a set of criteria for wilderness quiet parks that essentially boils down to a noise free interval of 15 minutes or more, which does not sound like a lot of time, but what we'd like to see is an average noise free interval of 15 minutes or more.

Which, again, it seems like that would be easy criteria to meet, but there are very few places left, not only in our country, but in the world, that meet that criteria.

CHAKRABARTI: That's noise free from human generated noises.

MIKKELSEN: Yes. Airplanes, cars, tractors, all that.

CHAKRABARTI: Got it. I think it's the airplanes that probably put a lot of places out of the running for --

MIKKELSEN: Don't get me started.

CHAKRABARTI: I will. I'll get you started when we come right back from this quick break, we are talking today about efforts to save the quietest places in the world. We'll be back. This is On Point.

Part II

CHAKRABARTI: Today we're speaking with Matt Mikkelsen. He's a field recordist and audio engineer with Quiet Parks International and he's executive director of Wilderness Quiet Parks. Now these are, this is an organization that's attempting to preserve or call attention to the need to preserve the world's quietest places. And here are some of your favorite quiet places.

(LISTENER MONTAGE)

I'm on the side of the road where I run many mornings, a couple of miles from my house. I'm in the middle of the marsh and it's low tide. So I hear the oysters popping all around me in every direction.

My favorite place is my garden in Northeast Missouri. I see all the lovely flowers, the trees, the bees. I hear the wind, the birds, the crickets, sometimes the cows.

I'm sitting at the base of some rapids on the Lamprey River, somewhere between New Market and Durham, New Hampshire. The water's pretty low. I can actually see a snapping turtle under the water to the left of me. That's the first I've ever seen that. He's about three feet away and about a foot below me. It's pretty neat. I can paddle my kayak up and I position right behind this rock right at the very end of the rapid, where I get stuck in this eddy. And my boat just floats. I don't have to do anything. And I can just listen.

CHAKRABARTI: On Point listeners are the best listeners because when we told folks, Matt, that we were going to do this hour with you, we asked them to go out to whatever their favorite quiet place was and record it. And we got so many beautiful recordings. We'll hear a few more in a little bit later in the show.

But, I didn't tell folks, speak in hushed tones when you're out there. People just did that naturally when surrounded by these other sounds of non-human life. Why do you think people do that?

MIKKELSEN: It's a really good question. I'm like so full of joy hearing those recordings. I just wanted to say thank you for sharing those with us.

It really brings a huge smile to my face, if you can't tell. I think I've been lucky to bring a lot of people into quiet places who have never experienced quiet before. And I think it's such a relief for us as humans and living in the kind of culture that we do to just take a moment and listen.

So rarely do we get the opportunity to just let go of any and all the things that are bothering us and our to do lists, and the time, and where we have to be and when. And just sit there and listen. And that is a very common theme, that when I bring people out into quiet, they become quiet. Subconsciously, they start talking in whispered tones. They just, they move more carefully. They can hear the sounds of their clothes rubbing. And there's this look and this feeling that they get, and I can see it in their eyes, of just kind of relief and joy. And that's what quiet has given me as well.

And it's such a powerful experience to have. What we say a lot is that if people ask, why is it important to save quiet? Oftentimes, they don't necessarily, haven't experienced that, I should say. And the need to preserve quiet becomes self-evident when you're in a quiet place.

CHAKRABARTI: The relief and my personal experience of it is almost, it's a kind of release, right? Because we are so bombarded by noise all the time that to the absence of that bombardment, it's like you can finally just decompress yourself into the environment around you. Now, Quiet Parks International quotes this number from the U.S. Department of Transportation that 97% of the American population is exposed to noise from aviation and highways, let alone all the other noises if you live in cities or towns. Quiet becoming extinct in the United States? How do we measure that?

MIKKELSEN: I would say quiet is extinct.

Not just in the United States, but in many parts of the world. And there are these slices of being able to listen to what it was like before that happened. But for the most part, most of us are subjected to these high noise levels that are bad for us. They're not good for our health.

And what we're trying to do is just recognize these few places that we have left around the world. Where you can get an insight into what it was like before we had engines, before the Industrial Revolution, before resource extraction, where you can really connect with nature in that very primitive way, where all of your senses are just devoted to experiencing that, that natural world and there's no interruptions from noise.

CHAKRABARTI: So you've mentioned this several times and I want to get into it in much more detail about the negative impacts of noise on health. And not just on human health, but like almost all living organisms do show some measurable change when they're in much noisier environments, from human beings all the way to tiny sea creatures.

So listen along with us, Matt, because we reached out to a couple of experts who know different parts of the animal kingdom. And one of them is fisheries biologist Paul Anderson. And in 2011, he wondered how seahorses respond to noise. So Anderson and his team placed 16 seahorses into quiet aquarium tanks, and 16 seahorses into loud tanks, and the louder tanks had much noisier pump equipment.

The team observed the seahorses for a month, and they quickly noticed a shift in what was happening to the animals in the loud tank. The seahorses were changing how they moored themselves.

PAUL ANDERSON: Seahorses like to hold on to their holdfasts. And so that's what they do most of the time. Something we found in the first week in particular, is that these fishes made more tail movements, readjusting themselves on their hold fast in the first week.

I think the interpretation of that is that they were adjusting to this noise stimulus that was probably also causing vibration in the tank, even going into the hold fast that they're holding on to.

CHAKRABARTI: Anderson says seahorses in the loud tank did return their movement to more or less baseline after the first week.

So things would seem normal from the outside. But after a month, the team did necropsies of all the seahorses. And they found remarkable differences between the seahorses in the quiet tanks and those in the loud tanks.

ANDERSON: The fish in the loud tanks had elevated cortisol. They also declined in weight and growth more so than did fish in quiet tanks.

We found some other physiological changes too. Probably one of the most noticeable is that they had an increase in a type of white blood cell in their white blood cells called heterophils that tend to increase as a result of chronic stress.

CHAKRABARTI: So the cells in the seahorse's bodies were changed with exposure to excessive noise.

Health changes, Matt, as you've mentioned, also occur in humans. Here's another person studying that. This is Erica Walker, and she says each unfamiliar or intrusive noise sets off a stress response in us.

ERICA WALKER: So it's that stress response that tells your body, hey, I recognize some sort of danger, and either I'm going to fight this danger, or I'm going to try to flee this danger.

But that consistent stimulation of that stress response can lead to the development of these risk factors. That lead us to these negative health outcomes ranging from heart attacks and strokes to anxiety, depression, et cetera, high blood pressure, all of these kinds of things.

CHAKRABARTI: Walker is assistant professor of epidemiology at the Brown University School of Public Health, where she also runs the Community Noise Lab.

So even if you feel like you're tuning out a sound, your body isn't. Noise can raise blood pressure and heart rate, as you heard, it can increase our risk of heart disease and diabetes, even slow down human digestion. Right now, Professor Walker's research is focused on two communities in rural Mississippi, the town of Gloster, and the other, the city of Quitman.

Both places have wood pellet plants, where wood is shredded and compressed into pellets for fuel, and that is a very loud operation, with industrial strength dryers and hammer mills.

WALKER: Maybe if there was a plant in the middle of downtown Boston, it wouldn't be as noticeable, but we're talking about putting these plants in communities where the sound level can get as low as 30 decibels, which is like quieter than a quiet library.

And so all of a sudden, you bring these industries into the  community and the decibels jump. About anywhere from 50 to 60 decibels. People talk about not being able to sleep, the children can't concentrate when they're studying.

CHAKRABARTI: Walker's team is looking at the health impacts of these plants on local children between the ages of 12 to 25, and she says they're in the data gathering phase right now, but plan to start analyzing what they find this year.

WALKER: You've collected lung function data, biometry. We've collected blood samples, their report cards. We've collected samples of their nails. We can look at nail cortisol levels, which is a marker for sort of sustained persistent stress. We've seen that the closer children live to the wood pellet plants, the more obese they are.

You'll be interested to tease out what aspects of that was associated with noise.

CHAKRABARTI: That's Erica Walker, Assistant Professor of Epidemiology at the Brown University School of Public Health. Matt, I wonder what you think about this. Because in listening to Professor Walker, it suddenly occurred to me that another really critical reason to try and preserve quiet places and also reduce excessive noise in places where there are people, is that, could this be another form of inequity amongst human beings? Because for folks who can escape noise and go to quiet places, they have that option. But I'm thinking of kids and families in louder places, in cities that can't escape that.

All of a sudden, it seems to me that's not actually very fair. That's a very inequitable situation.

MIKKELSEN: Absolutely. Yeah, I think you make a really good point. And listening to Professor Walker and their work, it's really incredible to see the correlations that they're drawing here. But if you look at a noise, a lot of cities have produced noise maps.

If you look at a noise map of a city and overlay it with a neighborhood overview, you can see that noisier neighborhoods are underserved neighborhoods. And when cities are doing planning work and noise mitigation work, those underserved communities are at the end of the chain of folks who will get and receive that noise mitigation. So it's absolutely, I think yet another kind of system that's been set up that oppresses more oppressed people first.

CHAKRABARTI: Why do you think it seems like only relatively recently? Excessive noise has become a focus for research because we have researched air pollution.

We've researched water pollution, land pollution for many decades. There's a lot of regulations in place to try and counter the effects of that kind of pollution. Less so on noise. Even in this day and age in, let's say, in localities that feel like they're progressive and want to make a, there's towns as healthy as possible.

Trucks are still ragingly loud. Motorcycles, trains, there's like neighborhood wars over leaf blowers. So it seems like we're only now figuring out that we ought to do something about all this noise pollution.

MIKKELSEN: Yeah, I think we're at a bit of a turning point, especially in our country, when it comes to noise.

Europe, as with most public health things, is a bit further ahead than us, but even still, Europe is very noisy when you look at it. But I think we're at the point where we're realizing that studying any number of the different types of pollution that we're subjected to, whether it's air or water or soil contamination.

We can't really look at that stuff in a vacuum, it's all related and it all impacts human health in ways that are interconnected. And we need to look at all aspects of what we're being subjected to with equal weight. And yeah, sound is, if you don't know a lot about sound, one of the amazing things to realize is that sound is vibration.

And when you think about low frequency sounds, so I'm talking about the sounds of like jet engines at a distance and distant traffic noise, these rumblings that you hear, those are vibrations, and those vibrations are passing through your body. And I'm no professor, but we can assume that can't be that good for us.

And like you had said earlier in the program, this isn't what we evolved to experience. It's only very recently in kind of the human arc that we're being subjected to these vibrations and to these sounds.

CHAKRABARTI: I live in a pretty noisy urban environment, but I suddenly thought that I'm incredibly fortunate. Because for more than an hour a day, I get to sit in this radio studio.

Which is silent, except for when I'm talking. And sometimes I find myself after the show, sitting here for an extra couple of minutes, and I didn't realize until just now, it's because it's so quiet, and it's peaceful. Wow, your show is really, the work that you're doing is really making me think of how important quiet actually is.

Now listen, you sent us a bunch of sound from quiet spaces, and I want to play another one quickly here. This is a field recording you made outside of Jefferson, Colorado and I really want folks to lean in and listen. Carefully.

(LIGHTNING AND THUNDERSTORM)

CHAKRABARTI: Did you get struck by lightning, Matt?

MIKKELSEN: I can't believe you guys played that sound. That's so awesome. That's the first time that sound has ever been publicly heard. Yeah, that's a sound recording of me almost dying. Not many people have a sound recording of their nearest death experience, but lucky me, I have the whole thing recorded in high fidelity.

I take a yearly thunderstorm chasing trip with a good friend of mine, Laura, who's also a phenomenal field recordist. And we go to record the sounds of storms in Colorado. Recording like dry, unrainy, unwindy thunder is, it's like the holy grail of field recording. So we go every year and that was in 2019.

And I did a really good job of putting myself in the path of a storm. And meteorologists call that type of lightning a bolt from the blue, because the storm was actually pretty far away from me. But the lightning comes from the top of the clouds, and can strike more than five miles away from the center of the storm.

And I just happened to be standing right next to the tree that it struck.

CHAKRABARTI: Oh my gosh.

MIKKELSEN: And my gosh, that was an experience.

Part III

CHAKRABARTI: Let's listen to a few more of your favorite quiet places.

(LISTENER MONTAGE)

I am sitting by a stream in City Creek Canyon. It runs down from the Wasatch Range and the Winter Mountains in Salt Lake City. I have been visiting this canyon for 35 years and it has literally saved my life.  

I'm on a swing hanging from my 80-foot cottonwood tree. Fields of corn surround me, and I can hear the leaves in the trees.

I'm on my parents' property here on the Tualatin River. The house is a log house built in 1950s. All the logs on the house came from the property. The property is mostly wooded. My grandparents bought the property back in 1959, I believe. I love it here.

CHAKRABARTI: So a few more of our listeners' favorite quiet places. As we've been talking, Matt, when in the context of preserving quiet places on planet Earth, we're talking about spaces that may be full of natural noises, but devoid of human made excessive noise. But I want to just take a second to talk about another kind of quiet.

A space that is so quiet that you begin to hear things that you've never heard before. Now this is a space called an anechoic chamber or a room without echoes.

STEVE ORFIELD: Most anechoic chambers are about, about 30 decibels, meaning that the quietness of a normal bedroom that ours is a minus 25 decibel chamber.

So it's 25 decibels below the threshold of human hearing. So we're in the animal hearing range in that chamber.

CHAKRABARTI: This is Steve Orfield. He runs the quietest room in the world, an anechoic chamber at Orfield Laboratories in Minneapolis, Minnesota. The chamber is made of an outer room of double walled steel and an inner room completely lined with one meter thick fiberglass wedges.

Floor, ceiling, walls, they're all covered.

ORFIELD: When you're in our chamber. Your hearing threshold becomes much, much more sensitive. And after 45 minutes or so, you can hear your heartbeat. You can hear your lungs flowing. You can hear the joints in your arms and legs scraping against each other. You can hear your carotid arteries beating your brain.

Some people can even hear their eyelashes as they blink.

CHAKRABARTI: Joints in your arms and legs scraping together, blood beating to your brain. Now these are sounds you've likely never heard before. Totally alien, even though they're from our own bodies. So you might think that would freak people out when they first experience it, but Orfield says it usually does the exact opposite.

ORFIELD: Once people start to realize that they're the sound, they're the silence, it's their body they're listening to. It surprises them. It doesn't, for the most part, doesn't make them nervous, for the most part, find it very peaceful. We actually do surveys before and after about how they were feeling when they entered and how they're feeling then when they come out.

And we find that people tend to be more peaceful. People tend to believe the silence is very comforting.

CHAKRABARTI: Comforting such that Orfield says his lab is now working to test how spending time in the quietest room in the world could be useful therapy for people like those on the autism spectrum, or folks who suffer from post traumatic stress disorder.

ORFIELD: PTSD causes startle responses. What we're trying to do is we're trying to look at whether spending an hour in the chamber, sitting in a chair in the dark can change the problems of PTSD, it can calm you down. It's known that silence is similar to using drugs. It can bring your body down in the same way that drugs can bring them down, chemically.

Nobody's ever done any research in a chamber anywhere near as quiet as ours.

CHAKRABARTI: That's Steve Orfield with Orfield Laboratories, which runs the quietest room in the world in Minneapolis, Minnesota. Matt, you're in St. Paul. Have you ever been in Steve's anechoic chamber?

MIKKELSEN: I have not been to Orfield Labs.

However, Steve and I are colleagues and I'm friends with other Orfield's in the family who have been doing really incredible work in this space of trying to figure out what is quiet and how does it impact us. So I don't know why I haven't been yet. It really is, it's silly. I'm here all the time.

CHAKRABARTI: (LAUGHS) Okay. I was just wondering because I want to visit now. It sounds like an incredible experience. And linking back again to the positive health impacts and psychological impacts that draining the world of excessive noise can have on people. So this leads me to, we've been talking about the need to preserve these quiet places on the planet.

And that how Quiet Parks International is working to identify these places where, as you said, there's at least 15 minutes of basically uninterrupted quiet sound. Once you identify those, though, now there's the question of how do you preserve it? Especially since, as you said earlier, airplanes are a big problem in terms of maintaining or interrupting natural sonic spaces.

MIKKELSEN: Yeah, I'd say the process is a bit different for every place that we work with. And while we've only awarded two in the United States, two wilderness quiet parks in the United States, we're working with probably 10 to 15, to try and figure out what that looks like for them. What's really important to us is that we have community buy in.

So not only are the folks who manage whatever piece of land that we're working with are bought in, but also the local community and all the local stakeholders agree that this is a valuable resource. For too long, conservation organizations have just come in and decided that a place needs to be preserved with no thought about how it would impact local communities.

So we're trying not to fall into that trap.

CHAKRABARTI: Can you give me an example? Because I see here that you've worked with Anza-Borrego Desert State Park in California. Yeah.

MIKKELSEN: Yes. So Anza-Borrego desert is, I think, the largest state park in the California state park system. It's located east of San Diego in the beautiful desert there.

And we've been working with them for a few years, first to establish what kind of quiet exists there, in what capacity quiet exists. And then to try and figure out how to bring that quiet experience as, like an interpretive resource, to their visitors. So we've been working with them for a few years to develop educational assets, to develop interpretive assets like maps and different brochures and things like that.

So that way when you visit Anza-Borrego State Park, you can go and try and find some quiet. And so that's one specific use case that's been evolving over the years. And then there are other instances where we've visited a place, and the community is really at the heart of what we do.

And most of the times surrounding these potential quiet parks, the community knows it's quiet. And they appreciate it's quiet and they want to protect it's quiet. So our hope is to be able to like empower and to give resources to these communities, to continue fighting to preserve these places.

CHAKRABARTI: Do you go so far as to advise communities on how to, again, airplanes keep coming up, right?

Because it's the one thing that even if there's an absence of human activity on the ground, flying over a quiet space can interrupt it. Do you advise communities on how to go to the FAA and advocate for changing flight paths?

MIKKELSEN: I usually advocate to not go to the FAA.

CHAKRABARTI: Okay.

MIKKELSEN: Mostly because we have been down that road.

The thing about air traffic is that it's obviously super prevalent. If you can look up like a live flight radar, if you look up like live flight radar and just look at any chunk of your state or the United States, you can see just how many thousands and thousands of planes are in the air at any given time.

So it's a huge problem and they don't have, there are certain like way points that planes use for navigation, but there aren't these kind of highways, similar to that we use with cars, to keep them all in one line. Even in our deepest wilderness areas and our biggest national parks, planes are flying over them constantly.

The FAA has two main concerns, first being safety. Thank you. Second being efficiency. So asking them to like reroute planes around a wilderness area or something like that isn't necessarily at the top of the list of stuff that they really want to do, it seems. And where we can have more impact is recognizing the threats to the soundscape that are on the ground, threats including like development, things like that, and try and stop that stuff.

But air traffic is going to exponentially increase over the next 10 or 15 years, and it already has exponentially increased from 30 years ago. It's a problem when you think about the noise exposure to folks, for sure.

CHAKRABARTI: Same thing with marine traffic, right? Oh my gosh. Yeah.

And I'm wondering about how do you preserve quiet places on the oceans? Because sound travels so differently in water that the sound could be generated very far away, but still have an impact on marine life, hundreds, if not thousands of miles away.

MIKKELSEN: Yeah, absolutely. Quiet in marine areas is like just as important as terrestrial areas.

But because we're humans, we're a bit biased, like this is the world that we get to hear. But if you stick a microphone in the ocean, you get to hear just how loud it is and how acutely it impacts all sorts of marine life. I hadn't heard about the seahorses before, and I'm fascinated by this experiment.

I have heard about whales and dolphins and coral being affected by noise, all these different things. But mitigating noise in water is really difficult, because sound travels so efficiently through water. It's one of those things where we really feel like, if I could wave a magic wand, I would create these corridors, we have marine sanctuaries.

We should be able to try and make them quieter. I would love if we could reroute boat traffic, and shipping traffic around those marine corridors. And same thing with the air traffic, wouldn't it be wonderful if we could have one or two national parks in the United States where planes couldn't fly over them?

As of right now, it seems it's not really on the horizon for us. But I think the more people that realize, oh, quiet is an important resource, not only for human enjoyment and our human health, but also for our ecosystems, the more likely we are to get to a point where maybe we could have something like that.

CHAKRABARTI: I want to ask you one more quick thing about the invisible ways that noise is having an impact on the world. Grouse drumming.

MIKKELSEN: Ah, yes. Lots of people don't know about grouse and the sound that a grouse makes, or even what a grouse is, I call it a chicken of the woods. It's like this kind of big plumpy bird that you find in a lot of places.

And they make this sound. The males make this sound where they flap their wings and beat them against their bodies. And it almost sounds like someone playing club music in the distance, and it starts out slow and then gets faster and faster. But because they communicate at such a low frequency, they're really subject to being interfered with by noise pollution, because it's the same kind of frequency spectrum.

And we've seen grouse populations just completely tank, especially sage grouse, over the last 20 years or so. And a lot of people are drawing correlations between the amount of noise pollution in these ecosystems and the successful kind of mating of the grouse.

CHAKRABARTI: Wow. Okay. As we turn towards the last few minutes of the show, Matt, I want to settle my own heart down a little by listening to some more places, some quiet places that you have recorded.

So this is Oregon Pipe Cactus National Monument on the U.S.-Mexico border. So let's hear what it sounds like there.

(SOUND PLAYS)

MIKKELSEN: Tell us a little bit about what we're hearing, Matt.

MIKKELSEN: The cactus wren is that really loud bird that you hear and that's, I'm sure, at dawn in one of the canyons in Organ Pipe Cactus National Monument, which during the weekend is one of the quietest places I've ever been, and during the weekday it's a military training area.

So you have these low flying fighter jets, and bombing ranges and things like that. But other than that, it's a no flight zone, no commercial flights can enter that airspace. So it's a sound recordists or a nature sound recordists', like, best- and worst-case scenario at the same time.

CHAKRABARTI: All right.

So here's the last one for the day. This is American Prairie Reserve in Montana, which is currently being evaluated for the Wilderness Quiet Park Award. And here is some sound from there.

(SOUND PLAYS)

CHAKRABARTI: Matt, as we wrap up here, just take a second to describe to me what happens to you, to your mind and your body.

MIKKELSEN: I think I take a deep breath. Because that's what happens, is I can take a deep breath. I can bring all of my problems and concerns and anxieties to quiet. And I can take a deep breath and feel peaceful. And I can connect to something that I think is a bit greater than myself, especially with this prairie recording.

This is what most of our country sounded like before we took the trees out and cleared the prairies and things like that. This is what sound awaits us if we can rewild our ecosystems. And what a treasure and what a joy.