Season 5: Episode 4

Do You Hear What I Hear?

What is sound? And what does it mean to listen? In this episode, we take a closer look at sound: what it is, how it works, and how what you hear may not be the same as your neighbor.

Guests

Resources

• The Evelyn Glennie Foundation

• The Evelyn Glennie Collection

Credits

Transcript

[00:00] INTRODUCTION

AMY: If you stand in front of a classroom full of kindergarteners and ask them what an ear is, chances are good that they will think you’re kind of silly. Everybody knows what ears are. Those floppy things on the sides of our heads. The things we hear with. But what if you were to pose that same question to a classroom full of spiders?

NATASHA: So this is going into the fun part of my research.

AMY: Dr. Natasha Mhatre researches how insects and spiders process sound at the University of Western Ontario. She says that scientists used to think that spiders couldn't hear airborne sound because they didn't seem to have any obvious ear-like structures.

NATASHA: That used to be the received wisdom. There's now different pieces of evidence from other labs, including some evidence we've just collected that suggest that they can hear airborne sound.

AMY: Where would their ears be?

NATASHA: So that's the big question.

AMY: Natasha says she and other researchers are now coming to understand that it’s not necessarily that spiders don’t have ears—they might just look really different than ours.

NATASHA: OK, so there's some evidence that one of the ways that they hear is when air hits the web of some spiders it makes the web move, and they can sense the vibration of the web.So they're kind of making their own eardrum. 

AMY: Ah-ha. The web is the ear.

NATASHA: The web is the ear.

AMY: How cool is that?

NATASHA: It is pretty neat. Because you can make whatever ear you want, right? If it gets damaged you can just make yourself a new ear. Really cool.

MUSIC

AMY: Welcome to Threshold, I'm Amy Martin, and we’re going to hear a lot more from Natasha in our next episode. But I wanted to start out with this fun little factoid about spiders just to shake up our perceptual framework. We think we know what ears are. We think we know what it means to listen. But those ideas are usually just drawn out of our own limited experience.

And speaking of things we think we know, but maybe don’t: what is sound? Like, if you had to define it right now, without looking anything up, what would you say? Even though I work in audio, I didn't really have a clear answer to that question before making this season of our show. Sound is one of those things that's so much part of my everyday life that it's easy to forget how mysterious it really is. It's everywhere, but it's invisible. It's flowing into my brain every waking moment—and when I'm asleep it turns out—affecting my mood, my energy level, my sense of connection to wherever I am, and whoever I'm with. But what is it, actually?

The answer to that is not as straightforward as you might expect. So in this episode, we're going to press pause on our timeline of listening to examine the nature of sound itself—what it is, how it moves, and how wildly different our experiences of it can be. We’re going to tap into a secret communication network happening all around us, pay another visit to the dolphins of Shark Bay, and talk to a world-famous composer about how much more there is to listening than what meets the ear.

INTRO MUSIC

[03:48] SEGMENT A

SWAINSON'S THRUSH

AMY: I'm walking through a Montana forest. The breeze is rustling through the trees. There’s a creek flowing nearby. And one of my favorite birds is unleashing its song, again and again.

SWAINSON'S THRUSH

AMY: It’s a Swainson’s thrush. I love this song—I think it sounds like a waterfall flowing up. Chances are good that you have a bird song you love too. And even if you don’t, almost all of us hear birds singing every day. This experience I’m having is in many ways totally ordinary. 

SWAINSON'S THRUSH

AMY: But if I zoom out a bit, and think about what’s actually happening here, it’s kind of marvelous — and mysterious. Something that originates inside the body of a small bird hidden in the branches above me is traveling across the forest and landing inside my ears, and ultimately in my mind, where it becomes this beautiful, melodic thing with the power to change my mood, and lift my spirits. I’m receiving something from this thrush; something is being transferred between us, and it’s affecting me. But what was that “something,” exactly? What is sound?

LILY: So at its heart it is an energy in the form of vibrational waves in matter.

AMY: Dr. Lily Wang is an engineer who teaches and studies acoustics at the University of Nebraska in Lincoln. She fell in love with sound as a child, the way many people do: through music.

LILY: I love singing. I've loved singing since I was a little girl and I've always been in choirs. And then I did also play piano.

AMY: I asked Lily to give me a crash course in the fundamentals of sound, and she started with the fact that there's a wide range of sound waves, and we can only hear a portion of them.

LILY: We call it the audible range. The most common definition of the range is 20 hertz to 20,000 hertz.

AMY: To help make those numbers mean something, here’s a tone moving across that whole range. It takes about 30 seconds.

TONE

AMY: But this so-called audible range should really be called the human audible range. Elephants, pigeons, and many other animals can hear well below what we can detect—that’s called infrasound— and all sorts of other creatures can hear way higher than we can, in the ultrasound range. Dogs can pick up frequencies twice as high as our upper limit, cats can hear four times higher, and many dolphins can hear seven or eight times higher than us—up to 150 thousand hertz. That's higher than almost all other vertebrates on the planet, except bats. Again, humans top out at around twenty thousand hertz—or significantly lower.

LILY: I really can't hear above 8000 hertz anymore. You know, there are bats in my house at certain times of the year and I can not hear them. Like I can see my children go...wooo!... or they twist their heads like they could hear that the bats are back and they're nesting, sadly, in our house and they're, like, squeaking. But it's at, like, it's probably at like ten, twelve thousand hertz. I do not hear it at all.

AMY: Here’s what ten thousand hertz sounds like. 

TONE

AMY: If you’re not hearing anything, don't worry, you are definitely not alone.

LILY: It's the most common disability among humans is that we lose hearing, and most often at that higher frequency.

AMY: In fact, some amount of hearing loss is almost inevitable as we age, and of course, some people don’t hear any airborne sound at all. We’re going to talk to one of those people later in this episode. But Lily says this measurement of how we hear sound waves moving through the air is really just one relatively narrow dimension of our lived experience of sound. All kinds of other factors affect our listening experience: the temperature and humidity of the air, what other sounds are happening at the same time, the shape and texture of the space we’re in. And that includes the most intimate space of all—our own individual bodies.

LILY: The shape of your head, the shape of your body. All these things are affecting how that sound wave approaches you. 

AMY: This is why our voices sound weird in our own ears when we hear ourselves on recordings. We're actually experiencing the sound very differently when it's coming at us in the air, through a speaker, versus hearing it from inside the place it's produced—the resonating chambers of our own bodies.

LILY: The fact that we are part of this experience does actually morph how that wave gets into our head.

AMY: So you and I could be walking right next to each other, listening to the same Swainson’s thrush calling in the forest, and the differences in the shapes of our bodies means we'll be hearing slightly different things. 

SWAINSON’S THRUSH

AMY: But however the sound waves are ultimately received, they all start the same way: with a vibration.

LILY: Something that is moving something back and forth.

AMY: From there, a whole lot of things happen, one after the other, really really quickly. So let's follow the journey of that Swainson's thrush song, step by step, from creation to reception.

MUSIC

AMY: In birds, as with humans, song begins with breath. This thrush pushes air out of its lungs and through a special organ called the syrinx. It's set up differently from the human larynx, or voice box, but the basic concept is the same. The bird squeezes the muscles around the syrinx, setting air molecules into  motion. When it opens its mouth, that vibration is then passed through the air molecule to molecule like a baton.

LILY: It's pushing these particles which push the next particles, which push the next particles.

AMY: It's an incredibly fast relay race moving from the bird…across the forest… 

SWAINSON'S THRUSH

AMY: …and into my ears.

LILY: But once it gets into the ear, it's traveling down, and it eventually hits a membrane that is physically attached to three of the smallest bones in your body.

AMY: That membrane is called the eardrum, and it is a lot like the tight, bouncy top of the drums we use to make music—except it’s only about a centimeter wide. That’s less than half an inch. The vibrating molecules of air hit that drum, making it shake. And that causes those teeny tiny bones, called the ossicles, to move, one after the other. Which shakes a second membrane…

LILY: ...that is then connected to fluid inside the cochlea.

AMY: The cochlea is a fluid-filled tube, coiled up like a snail shell, or the world's tiniest cinnamon roll. As the vibration that began with the breath of the bird is transferred into the cochlea, it sends ripples through the fluid inside, almost waves rolling across a miniature ocean.

MUSIC and WAVES

AMY: And lining the inside the cochlea, swaying in the fluid, guess what we find? Cilia. Tiny little hairs, like the ones that grow on the bodies of baby corals. Under a microscope, they look like sea grasses, flexing and bending as the waves of sound roll over them.

MUSIC and WAVES

AMY: And as they move in response to the sound energy, the cilia perform one of the greatest magic tricks in the human body. They transform this physical vibration into a spark of electricity which then shoots off to the brain through the auditory nerve where we process it as a sound.

LILY: And all this happens so fast, like so fast, like, in an instant.

AMY: Three hundred and forty three meters per second, give or take. More than three football fields in the snap of a finger.

LILY: So quickly...it's just miraculous.

AMY: So to recap the process: the vibration starts in the body of the bird. That energy is passed across the forest, into my ear canals, where it hits the drum that moves the bones that hit the other drum that shakes the fluid which bends the cilia that turn the vibration into electricity that goes to my brain. In less than a second.

SWAINSON'S THRUSH

AMY: And that’s the simplified version.

But as quickly as this vibration is transferred from the bird to me as I walk through the forest, the movement of sound in air is actually relatively slow. Sound moves more than four times faster in water compared to the air.

SOUND: boat, waves

STEPHANIE:S Ah, this, this.

LAURA: This is what we need.

STEPHANIE: This is it. This is paradise.

AMY: We’ll have more after this short break.

Break

[13:55] SEGMENT B

AMY: Welcome back to Threshold, I’m Amy Martin, and I’m in Shark Bay, Western Australia, scanning the horizon for dolphins.

AMY: I keep seeing something way out there.

STEPHANIE: Yeah, that was another dolphin, yeah, yeah.

AMY: That’s Stephanie King, co-director of Shark Bay Dolphin Research.

STEPHANIE: So we're approaching what we call glass—there's hardly any wind. And then you really see how many dolphins there are in Shark Bay because you just start to see them everywhere.

AMY: Ah, so cool.

AMY: In our first episode, we met Stephanie and her field team, and a few of the two or three thousand dolphins that live in these waters. Now it’s the afternoon of that same day. The heat is upon us, the wind has died down, and we're moving slowly across the water.

AMY: It's the most beautiful blue green water, it's just perfect.

AMY: Up ahead, a small group of dolphins is gathered at the surface. They’re not swimming, or jumping. They’re just kind of hanging out there in the calm, quiet waters. Stephanie explains what’s going on.

STEPHANIE: You'll sometimes see dolphins in Shark Bay what we call “snagging.” This is when they're resting at the surface. So the whole body is just flat on the surface. And it was because in Australia you snag sausages on the barbie. Like snagging…they’re called snaggers on the barbie. And it’s just like a sausage lying at the surface.

AMY: But these floating sausages are actually much more active than they appear. A dolphin doesn’t lose consciousness when it rests, or at least not all the way. Half of its brain remains engaged in the work of breathing—which it needs to come to the surface to do—and stays alert to what's happening around it. And that means listening.

SPEAKER TURNS ON

STEPHANIE: Do you have whistles?

LAURA: No, buzzes.

AMY: Researcher Laura Palmer flips on the speaker in the boat connected to the underwater microphones, and we’re suddenly dropped into a conversation. 

DOLPHINS BUZZING

AMY: These are echolocation buzzes —pulses of sound the dolphins send out in order to gather information about their world. 

DOLPHINS BUZZING

STEPHANIE: They wait for the returning echo. And so the closer they get to a fish, the more they are echolocating. So they can use the returning echo to work out distance and shape.

DOLPHINS BUZZING

AMY: It’s remarkable to be able to listen in as the dolphins do this, but it would be even more mind-blowing to to experience these sounds the way they do.

MUSIC

AMY: Dolphins aren’t only detecting a much wider range of sounds than we can—the whole nature of their sonic experience is something we can only sort of guess at. These echolocation buzzes are beams of acoustic attention. And they come back to the dolphins packed full of information that their brains have evolved to process at lightning speed.

AMY: So what sounds to us like a continuous buzz, to them, it's like really fast echolocating happening?

STEPHANIE: Exactly. Really, really fast clicks. So they're like pulsed vocalizations. And they produce them so rapidly, so sometimes it sounds like it's almost a continuous vocalization.

AMY: Dolphins can actually use echolocation to perceive the insides of objects. If I jumped in the water with this group, they would be able to sense not just my outer surfaces, but my bones and lungs. They would perceive me in a way I could never perceive myself. And they’d be doing it using sound. 

STEPHANIE: Here we go. Snaggers.

AMY: We’ve come upon another group of resting dolphins.

STEPHANIE: Snagging, see, just resting at that surface, like a…

AMY: Sausage on the barbie.

STEPHANIE: Sausage on the barbecue. Exactly.

BUZZES

AMY: Stephanie says dolphins use echolocation primarily to help them find food and for navigation. But even now, when they appear to be doing little to nothing, there is some echolocating going on. It’s like they’re casually scanning the environment, just keeping an ear out. Except that ear isn’t where we might expect it to be on their bodies.

STEPHANIE: They receive sound through the lower jaw. And that sound then goes up to the middle and inner ear. So when they're snagging like that and resting, you sometimes see them—the lower jaw is still in the water, and they're kind of moving their head side to side as if they're scanning, right? They're not vocalizing. They're actually listening for sounds of other dolphins, if you like. So we typically see that when maybe they're waiting for a dolphin to catch up, or there’s about to be a join. They'll turn around and they're scanning, and they've obviously detected something, and then they're having a good listen to see who might be close by.

AMY: But with dolphins and other animals that live in the water, the whole idea of “close by” has to be redefined. Acoustic vibrations don’t only happen faster underwater than in air, they also do a better job of holding on to their power. As the vibration is transferred from molecule to molecule, it doesn’t lose as much energy with each pass of the baton. That means underwater sounds can stay loud for a much longer time. So what feels very far away in human, terrestrial life might feel quite nearby to a fish, or a seal, or a dolphin.

LAURA: And Rockette just surfaced 80 degrees.

AMY: There’s a little flurry of extra buzzing from the group as a dolphin named Rockette pops up and joins them. But there’s no visible change in the dolphins’ faces—it’s not like they’re opening their mouths to echolocate. I ask Stephanie how they’re producing these sounds, and she says, as with our vocalizations, it begins with air pushing through tissues in the dolphins’ bodies.

STEPHANIE: They basically have these phonic lips—these two lips they can push together and then force air through. That then causes vibrations of different tissues within that chamber. And it's the tissue vibration which creates a sound essentially. 

BUZZES

AMY: I love how they're performing right on cue. As you're talking about it, they start doing it.

STEPHANIE: Yeah, yeah!

BUZZES

AMY: That vibration then passes through a pillow of fatty tissue in their foreheads called the melon. It acts as a sort of acoustic lens, focusing and amplifying the sound, which is then projected out through their heads.

MUSIC

AMY: We think of making sound as one thing, and receiving it as another. But one of the things I find most intriguing about echolocation is that it’s both, at once. It’s a way of making sound in order to listen. It takes the whole idea of “active listening” to a completely different level—dolphins can decide to shoot a beam of listening toward another dolphin or an approaching fish, kind of like the way we might flip on a flashlight in order to see into a dark corner of a room. 

MUSIC

AMY: And they can manipulate that echolocation beam—they can make it stronger or weaker, wider or narrower. And if something attracts their attention, they can turn up the dial instantaneously, and send out a bright, strong pulse of acoustic energy, homing in on whatever it is they want to investigate. That’s what seems to have happened with Rockette, because she’s suddenly left her group and zoomed right under our boat.

STEPHANIE: Here we go. Rockette in the bow. Hi Rockette!

AMY: Hey beauty! Oh wow. Right underneath us. 

STEPHANIE: This is good, this is good. 

AMY: Oh my gosh. I mean, I could reach out my hand and touch her. Wow.

AMY: It’s not us she’s curious about—it’s a patch of seagrass below us. In the crystal clear water, we can see her twisting and turning herself through it.

STEPHANIE: So we saw Rockette just come up and rub herself in a seagrass patch, and we see that a lot with the dolphins, and we'll call it seagrass play. Or they seem to come up and drape over their body and even rub themselves against it. I think it just because it feels nice. But you see that quite often. And she obviously peeled off from the group, spotted that seagrass patch and went over there and started rubbing herself underneath it before returning to the group. 

AMY: It looked a little bit like a dog rolling on a mat.

STEPHANIE: Yeah, exactly, and you know, they do that. It's fun. They enjoy it, feels good. Same for the dolphins.

AMY: Lots of animals use echolocation—orcas and sperm whales, some small burrowing land mammals, and of course the most famous echo-locators of all, bats. The common denominator here is darkness;  where vision is diminished, the clicks, chirps, and buzzes of echolocation can help animals navigate their worlds. Humans can learn to echolocate too. Many people with visual disabilities become experts in it. But even the most highly skilled person can’t come close to what dolphins can do. 

BUZZ

AMY: Echolocation is only one of the ways dolphins use sound. In future episodes we’ll be coming back to Shark Bay to listen to their whistles and pops—sounds they use to communicate with each other, and even to identify themselves. But now it’s time to return to the terrestrial realm, to meet these mysterious creatures that are using sound in another fascinating way.

TREEHOPPER MATING CALLS

AMY: We’ll have more after this short break.

Break

[24:22] Segment C

TREEHOPPER MATING CALLS

REX: So now we're hearing their mating signals.

AMY: Welcome back to Threshold, I’m Amy Martin, and we're back in the U.S. now, with Dr. Rex Cocroft and a group of wild animals. I’m not going to tell you what they are right away — just listen, and guess.

TREEHOPPER MATING CALLS

REX: Two or three different males.

AMY: So cool!

AMY: Here’s a hint: these animals are much, much, much smaller than dolphins.

TREEHOPPER CALLS

AMY: They live all over the world, and millions of people walk by them every day as they make these sounds. But we don't hear a thing.

TREEHOPPER CALLS

AMY: This sound is made by a treehopper. A teeny little insect, about the size of a sunflower seed without the shell. It communicates by shaking its abdomen, which sends waves of vibrations through its legs and out into the stems and leaves of plants. Other treehoppers can feel the vibrations with their legs, and they often respond with their own belly shakes.

REX: And it doesn't look like they're doing anything at all. They're stationary. If you're really close, you can see their abdomen moving when they signal. But otherwise it just looks like nothing is happening.

TREEHOPPER CALLS

AMY: And ordinarily, it also doesn’t sound like anything is happening. These treehopper calls don’t get broadcast out into the open air. It’s not just that these insects are small, and their calls are quiet. The vibrations they make don’t leave the body of the plant. We’re only able to hear them now because Rex has hooked up a special microphone to the plants, and connected it to some speakers.

REX: But if I turn the speaker down, you don't hear anything. And we're standing right next to this plant and you could put your ears right next to it, you really don't hear anything.

AMY: So these little insects are talking to each other through a secret world of sound called the vibroscape. Instead of air or water, these acoustic waves are moving through the bodies of living plants.

REX: It's like they take a different transect through acoustic space and put together sound in ways that we never thought to do.

AMY: So what is going on here? How is it possible that these sounds are happening but we can't hear them? And how did Rex break the code?

MUSIC

AMY: Well it helps that he had an early interest in music, like Lily Wang. Later, he combined that with a love of biology and animal communication. He studied frogs at first, but one day in the 1990s, Rex decided to find out if treehoppers had anything to say.

REX: I just walked out onto a meadow near where I lived—I was at Cornell, so this was upstate New York, a very beautiful place in the summer.

MUSIC

REX: I had a tape recorder, it was a cassette tape recorder. And headphones.

AMY: He found a goldenrod plant with some treehoppers on it, and leaned a microphone right up against it.

REX: And immediately I heard these wonderful sounds. I'd never heard it before, just this tiny insect, this beautiful song. And then I was hooked. I never looked back.

TREEHOPPER

REX: It was a sound that I was completely unfamiliar with and I could be confident that no human had ever heard that sound before. And that's still true with most insects that communicate through plants, you listen to them and probably nobody's ever heard that sound before.

AMY: And that’s basically just because we haven’t been listening. We couldn’t hear anything, so we thought there was nothing to hear.

TREEHOPPER

AMY: It’s almost like the treehoppers turn the plants—and their own bodies—into musical instruments. That’s partly what captivated Rex about these sounds the first time he heard them.

REX: To me it was totally different from what I expected, because it had... it was like harmonically structured and it was changing in pitch, and it was very exciting.

TREEHOPPER

AMY: Before we knew anything about their sonic lives, treehoppers had attracted attention because of their appearance. 

REX: They look like miniature cicadas and they have a kind of roof over their back that in many cases is very elaborate and whose function we still don't really know in many cases.

AMY: The treehoppers Rex studies the most are called thorn bugs—they look like rose thorns that can walk. Other treehoppers look like they have sand castles on their heads. Or bird droppings.

REX: And others have what looks like a little Starship Enterprise on their back, a lot of interesting forms. And others it's just a smooth roof.

AMY: So treehoppers are kind of the quirky rockstars of the insect world, pushing the boundaries of fashion and sound. This next one might be my favorite. Its scientific name is potnia brevicornis, but I think of it as rage against the machine.

POTNIA BREVICORNIS

AMY: Again, this hidden world of acoustic signaling is called the vibroscape. And I love that term, but it also made me wonder…since waves of vibration are happening anywhere there’s sound, isn’t the vibroscape sort of…everywhere? I put the question to Rex.

AMY: Is there a sharply defined line between a sound and a vibration? Because my understanding is that all sounds are vibrations. So why aren’t all vibrations sounds?

REX: They're very closely connected. And it depends on the sensory structures that you use to pick them up and how your nervous system then relays that information to your brain. 

AMY: We can experiment on ourselves in real time to understand this. If you’re playing this episode through a speaker in your house or your car right now, and you crank up the volume, you might be able to feel the music vibrating the floor or the steering wheel. 

MUSIC

AMY: If you're a person who hears airborne sound, you can also hear those waves as they hit your ear drums. The waves of vibration have the same source—the music—but they can be perceived through two different sensory systems.

REX: It's all the same thing, it's all mechanical energy that's propagating through an environment, whether it's a structure, whether it's the air, whether it's the water. But you have to have a different kind of sensor to pick it up. And that's actually a really profound difference when it comes to the receiver side. So for us, our vibration sensors are totally different from our ears, and the information from those...we feel it differently. It goes to different parts of our brain. And so that's what makes it so different for us.

AMY: For us.

REX: For us. Right. For us.

AMY: Our experience of these waves of vibration is bifurcated into two different sensory systems—hearing and touch. But that’s just a reflection of the way our bodies happen to be put together.

REX: For other animals, they may be just two sides of the same coin. Like the ones that I study, these insects with their six legs, and they have vibration sensors in their legs...but some of those vibration sensors also act as pickups for airborne sound...and I don't honestly know how they tell the difference, sometimes. How do they know if it's a sound or a vibration if they're picking it up through their legs, and I'm not...I'm not really sure the answer to that.

TREEHOPPER

AMY: Or maybe the whole question of what defines sound versus vibration only makes sense from within our own perceptual framework. Maybe, if your senses of touch and hearing are more unified, there is no differentiation, really.

EVELYN: We're actually incredibly gifted listeners. You know, that is inherent to being a human being. We have the capacity to listen. I think it's a categorization of the word “listen” that gets really confused.

AMY: Dame Evelyn Glennie is a world-renowned percussionist and composer. She's also Deaf—she doesn’t hear airborne sound waves. But she says listening is available to everyone.

EVELYN: You know, we think about hearing and that's something that can be measured. That's something that, you know, medically, we can see whether that person can hear a certain frequency at a certain volume. However, listening is not something that can be measured medically. Someone can be born Deaf but they can be amazing listeners. 

AMY: Evelyn grew up in rural northern Scotland, helping out on her family’s farm. And she says the patience that farming requires gave her some of her first, formative lessons in listening.

EVELYN: Because listening is all about patience, that I have learned over time. So you can't force a field to grow corn any quicker than it will grow the corn, according to the season and the weather. You know you can’t dictate when a sheep will give birth to a lamb. It will just naturally give birth to a lamb as and when that time is right. You know, there are certain things that just need to happen naturally. And so I think that is very much to do with listening, you know, is that we can control a certain amount, but ultimately we also have to work in partnership with the existence that we're in, with the environment that we're in.

AMY: Evelyn had already exhibited a strong interest in and talent for music when she began to lose her hearing around the age of eight. 

EVELYN: I realized that one aspect of the body was no longer working the way it used to work.

AMY: But this change did not stop her development as a musician. In fact, it seems to have enhanced it. When she began studying percussion at age 12, her teacher suggested she take out her hearing aids, and tune in to other ways of sensing the music. That’s when she started to learn how to listen with her whole body—to pay attention to the vibroscape. 

EVELYN: It's simply the knowledge that sound is vibration. That is what sound is. And therefore, our bodies are a resonating chamber. 

TRIANGLE DING  

EVELYN: So if I'm playing a glockenspiel, or cymbal, or triangle, or anything with high frequencies, it's more than likely going to touch the face and the upper part of the body.

TIMPANI HIT

EVELYN: However with low, low sounds, such as playing bass drum or timpani or, you know, anything with a really low, resonant sound, obviously the vibration is quite wider and bigger. And that will reach a larger part of your lower part of the body. So you know, your tummy, your chest, tummy down, your legs, your feet through the stage and so on. 

AMY: Evelyn has developed her ability to feel differences in pitch, tone, and musical color at a much subtler level than most people, and used those skills to become one of the most celebrated percussionists of all time. She composes for the concert hall, film, and television, and performs all over the world. She’s won multiple Grammy awards, the Polar Prize, and a long list of other honors. Clearly, she has a musical force in her that was not going to be denied, no matter what. But even though we’re not all going to become musicians of Evelyn’s caliber, she insists anyone can learn to sense sound as a whole-body experience.

EVELYN: You know, the brain is an extraordinary thing, and it will re…kind of…jig itself in so many different ways. But it does need time. It really needs time. 

AMY: It also needs courage and freedom to explore. And Evelyn has cultivated those qualities in herself, along with a beautiful sense of play. Despite all of her success and expertise, she positions herself as a learner. She greets an instrument or a piece of music like she’s greeting a friend—she doesn’t assume anything. She asks questions. Starts a conversation.

EVELYN: I'm very thankful just to have a curious take on things. And I think that's really what it boils down to. 

EVELYN: You know, if I'm picking up, let's say a waterphone or something, 

AMY: A waterphone looks like the mutant offspring of a pie pan and a hedgehog. It has a round base with spiky rods attached to it, which can be played with mallets or a bow. The music you’re hearing is from a video on Evelyn’s YouTube channel, called “Waterphone Improvisation.”

EVELYN: You know, the first thing I'll do is look at the object. What is it made of? You know, is it metal? Is it wood? Is it skin? Is it ceramic? Is it glass? Is it porcelain? What is it? I look at the size of it. Is it handheld? Is it something that you have to sit to play? Is it something that you stand to play? Is it something that you use mallets to play or sticks to play and so on. 

MUSIC

EVELYN: So immediately before I've even struck something, the whole body is involved, you know, so you're not even, you know, thinking about this really, from a musical point of view. It's simply from a construction point of view and how you can allow the body to be an extension of this object so that there's no longer the player, the instrument, their audience, their music, the this, the that. 

MUSIC

EVELYN: So how is this body sort of merging into this instrument?

MUSIC

EVELYN: And then I'm like a kid, so I don't go on the internet to find out how to play the instrument. I just say, Evelyn, what are you going to do with this instrument?

MUSIC

EVELYN: So there's no boundaries, no expectations, nothing. 

MUSIC

EVELYN: So we sound creators are sound artists, you know, we're painting sound, into a space.

EVELYN: So you just sort of begin to think, oh yeah, that's a fat sound because it's felt through your, your, your tummy or your lower part. Oh, that's a much thinner sound or that's a weak sound or, ooo, this is as far as I can go dynamically, without maybe causing harm to the instrument. These are the different objects I can use, and bit by bit you build up your kind of color palette. 

EVELYN: And so when you're looking at an instrument and engaging with that instrument, you're basically finding out all of the sound colors as you possibly can in the environment that you're in that that particular instrument can produce through the imagination that you have and that you're willing to engage with.

EVELYN: And that is that. 

AMY: Evelyn has become famous as a maker of sounds, but she says her primary purpose is to teach the world to listen. In fact, she created a foundation to advance that mission.

EVELYN: Listening is about being in the here and now. It's about living each day and taking the time to experience what is right in front of you. So it's kind of stripping down all of the complications, releasing all of the baggage that's on our shoulders, all of the expectations. It is just simply being, and that's very liberating.

AMY: I wanted to expand the boundaries of my own listening abilities, and see if I could tap into the secret treehopper communication channel that Rex had told me about. So I bought a small contact microphone, and attached it to some plants. A lot of plants. And mostly, I heard wind and plant stems bumping into each other.

HICKORY HILLS PIEZO HAND ON STEM

AMY: But I got better with practice, and one day, in a park in Iowa City, the magic happened.

MYSTERY BUG

AMY: I couldn't see who was making this noise, or where it was, but somebody was talking.

MYSTERY BUG

AMY: And kind of...humming?

MYSTERY BUG

AMY: I sent this recording to Rex Cocroft, and he said it was definitely something in the cicada group, probably a leafhopper, but he couldn't say for sure which one. He said it wasn't a sound he had recorded—and chances were, no one else had heard or recorded it either. Which felt pretty extraordinary. It's not very often that I can say I might have recorded a sound no other human has ever heard. And now you've heard it too.

MYSTERY BUG

AMY: We don’t know what it’s like to be a treehopper, hearing—or hear-feeling—the call of another treehopper through a plant. Just like with the dolphins, we can't get inside their experience. We can get closer to guessing what our fellow humans are experiencing, but even then, we can't really know. Some people feel vibrations very sensitively. Other people hear a huge range of airborne sound, or none at all. And whatever we’re hearing and feeling right now, that experience is bound to change over time, often in ways we can’t control. Sound is ephemeral and ever-changing. And so is our experience of it. 

AMY: So you know that Christmas carol that asks, “do you hear what I hear?” Well now I know that the answer is no, I don’t. Or…maybe, kind of, sometimes? But that difference is part of what connects us. No one person or even species can hear everything. But together we are a planetary ensemble of listeners, each us making our own entirely unique contributions.…the treehoppers and the spiders, the dolphins and the percussionists, the corals and the fishes, and you and me.

CREDITS

AMY: This episode of Threshold was written, reported, and produced by Amy Martin, with help from managing editor Erika Janik and assistant producer Sam Moore. Music by Todd Sickafoose.  Post-production by Alan Douches. Fact checking by Sam Moore. Special thanks to Stephanie King for some of the dolphin sounds you heard in this episode, to Rex Cocroft for the use of his treehopper recordings, and to Evelyn Glennie for the use of her music. Check out Evelyn’s YouTube channel, and watch her do this waterphone improvisation, or any of her other videos there. You can find it by searching for Dame Evelyn Glennie on YouTube, and you can also find a link to it on our website, and in the show notes. This show is made by Auricle Productions, a non-profit organization powered by listener donations. Deneen Wiske is our executive director. Learn more at thresholdpodcast.org