Space Audity: The challenges of space communication

Art by Jon McCormack.

This episode was written and produced by Jack Higgins.

We've all heard the iconic recordings from the Apollo missions. But how exactly does NASA manage to run live audio between Earth and the moon? And how might we chat with astronauts on Mars and beyond? Featuring Astronaut Peggy Whitson, NASA Audio Engineer Alexandria Perryman, and Astrophysicist Paul Sutter.


MUSIC FEATURED IN THIS EPISODE

Are We Loose Yet Bodytonic
Algo Rhythm Natural by Sound of Picture
Gathering by Sound of Picture
If I Lost You (with Emily C Browning and Why the Face) by Ariza
Raining the Blues by Ernie Barton
Fragile Do Not Drop by Sound of Picture
Dirty Wallpaper by Lemuel
Roadside Bunkhouse by Truck Stop
Andromeda by Tony Anderson
Thumbscrew by Sketchbook 2
Night Vision by Sound of Picture
Vega by SVVN
Sequence by Greg Thomas


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Check out Ask a Spaceman wherever you get your podcasts.

View Transcript ▶︎

[music in]

With the rise of cell phones, it’s never been easier to get in touch. You just unlock your phone [SFX], tap a name [SFX], and in just a few seconds [SFX: Phone ringing], you can literally talk to someone on the other side of the planet [SFX: “Konnichiwa”]. We’re all used to it by now, but the technology that makes that call possible is pretty incredible.

When you initiate that phone call [SFX: phone dial], the antennae on your cell phone beams [SFX: laser sound] a radio signal [SFX: radio signal] to a nearby cell tower. The cell tower then sends this signal over a fiber optic line [SFX: electricity] to a switching center [SFX: switches and plugin sounds]. From there, the signal is connected to another cell tower [SFX: electricity], which then beams [SFX: radio signal] it to the phone of whoever you’re calling [SFX: hello].

That’s complicated enough, but what happens when you need to talk to someone who’s not even on this planet?

[SFX clip: Key sound SFX: Houston this is Neil, radio check...]

You're listening to Twenty Thousand Hertz.

[SFX clip: NASA: Neil this is Houston...]

[music out]

When you’re orbiting the Earth at over 17,000 miles an hour, communication gets really tricky.

[music in]

Alexandria: They use what's considered space to ground loops. It's radio frequency, and because they're moving around the earth so quickly, they have to bounce off of satellites in order for it to get transmitted down.

Alexandria Perryman is an audio engineer at the Johnson Space Center in Houston. Yep, the same Houston that the astronauts are always talking to...

[SFX: “Houston” montage]

When communication from a space mission reaches ground control, it’s Alexandria and her colleagues who broadcast the audio to the public.

Alexandra: We have the space to ground loops going, running, 24/7, and it's all being recorded.

Alexandria: And so what we do with our audio is clean it and put it out to the public live. So the same space to ground loops that the mission control was talking into, I have control of that to put it out on NASA TV and Facebook Live and use it for other things for the public to be able to hear.

Almost all of the audio that comes into mission control gets immediately rebroadcast.

Alexandria: When we're live on air, say we're doing a space walk what you guys are hearing is what we're hearing.

[music out]

The fact that we can run live audio between Earth and space is pretty mind boggling. One of the first things you’ll learn in physics class is that sound can’t travel in a vacuum.

Paul: Sound at its most simplest level is pressure waves, waves of varying pressure in a medium like air or water.

This is Paul Sutter. He’s an astrophysicist at Stony Brook University and the Flat Iron Institute in New York City.

Paul: As sound waves propagate out, you can watch microscopically, the little air molecules [SFX: wind and dust/debris] or water molecules [SFX: moving water, bubbles] scrunch together [SFX: sounds are sucked into center] when the wave hits a peak and then spread out as the wave hits a trough [SFX: sounds pan across stereo spectrum]. And we create those pressure waves by shoving air through our throat and vibrating our vocal chords [SFX: singing]. Those pressure waves travel through the medium into our ears and where they vibrate our eardrums [SFX: vibration]. The little air molecules next to our eardrums wiggle it back and forth, [SFX: electrical sounds] and that it translates into a signal that we interpret in our brains.

To create this ripple effect, sound waves have to have something to travel through.

[music in]

Paul: The key part of all this is that it requires a medium, so you need some sort of gas or fluid that can have a pressure in order to sustain sound waves.

But in the vacuum of space, there’s virtually no pressure at all, so those soundwaves have nothing to travel through.

Paul: So we have to transform our sound waves into something that can transmit through vacuum, and light can travel through a vacuum.

What we normally think of as “light” is really just the tip of the iceberg.

Paul: Light comes in many, many different kinds of wavelengths. Some of them we can see, like red or green or blue, and in many, many wavelengths that we can't see, like infrared or microwave or radio. And radio waves are pretty fantastic for transmitting through space. They can cut through a lot of interstellar dust pretty easily, and so radio waves are our preferred form of communication in space.

Once you transform a soundwave into a radio wave, you can send it over huge distances, through the air, under water, or, in the case of space, [music out] across an empty vacuum.

[SFX: Radio static/tuning]

If you ever listen to the radio in the car, you’ve probably had the strange experience of picking up two stations at once. [SFX: song 1 + song 2 playing at once with heavy radio static]

This happens because both stations are broadcasting at about the same frequency.

This interference usually goes away pretty fast as you drive farther away from one signal, and closer to the other one. [SFX: one song stutters and fades out while the other becomes more clear, then quickly ends like you turned off the radio]

But the signals going to and from space are much stronger than your local radio station. To reduce radio interference, different radio bands get designated for different types of communication. For instance, the International Space Station now uses four specific bands.

Peggy: Originally, we had two S-band communication systems. And now, we have four bands of communication, two on S-band and two on KU-band.

This is Peggy Whitson, the first female commander of the International Space Station, or ISS. The definitions of S-band and KU-band get pretty technical. The point is, the more radio bands you have to work with, the more lines of communication you have.

Peggy: If everybody's doing different experiments, we need more bands of communication so people can be talking to different team members.

These astronauts might be talking to mission control in the US, Japan and Germany all at once, meaning their radio signals are going all over the world. To make this possible, these transmissions have to go through a Tracking and Data Relay Satellite, also known as TDRS.

[music in]

Peggy: It's being transmitted into geosynchronous orbit, which is 22,000 miles out. There are half a dozen satellites that sit, different places around the planet and they rotate as the planet rotates, so they're always in the same place above the planet.

These TDRS satellites work almost like cell phone towers in space, transmitting messages between ground control and the astronauts in orbit. [SFX: Satellite beeping]

Peggy: [SFX: Peggy speaks as through a radio, panning left to right] And so, the signal gets sent to those satellites out there at 22,000 miles then it gets bounced back to us at 250 miles above the earth. But we're traveling at 17,500 miles an hour so we have to switch to different satellites as we're going around the world to maintain that communication.

All of this happens in milliseconds.

Peggy: I always think it's funny that it goes from the ground, out 22,000 miles then back to 250 miles above the earth before we actually hear it.

[music out]

Of course, the astronauts on the ISS aren’t always working. In their free time, they sometimes check in to see if anyone down on Earth wants to chat, using what’s called a “ham radio”. “Ham radio” essentially means “amateur radio,” and it covers any use of radio communication for non-commercial or unofficial purposes. Here’s astronaut Doug Wheelock using the onboard ham radio to talk to someone in Texas.

[SFX clip: Doug Wheelock: Whiskey Five Sugar Sugar Victor, we’ve got you loud and clear. Welcome aboard the International Space Station, number Alpha One Sugar Sugar.

Club Owner: Thank you for answering the call, Doug I just want you to know our club is 90 miles southeast of Houston and we’re looking forward to getting home, and maybe we can have dinner when you get back. Appreciate you answering the call. Whiskey Five Sugar Sugar Victor.]

[music in]

Now that the ISS has two extra radio bands to work with, they can use these extra channels for the more casual interactions.

Peggy: The ham radio is not used as much these days because we have four channels of com now. We do a lot of school talks nowadays to students, projecting our video, and they get direct com via the S-band or the KU-band assets on board the station.

For Alexandria, these school talks are some of the best days on the job.

Alexandria: I love the part where I'm doing a live interview with, say, that astronaut on the ISS and an elementary school. And they're communicating through Skype and I'm coordinating the audio through, just seeing the kids' faces light up when the astronaut floats across the screen. That moment, I was like, "I officially have the coolest job ever."

[SFX clip: Aiden: Hi, my name is Aiden. How would you describe the view from the International Space Station? Over!

Akihiko Hoshide: I can describe it in one word, and it is, “COOL!”]

Alexandria: These kids, they come there and they're dressed up as astronauts and they get to ask their question. And I'm the one who gets to push their audio through to the astronaut. And that may be a moment they think of for the rest of their life.

[music out]

The systems that make these transmissions possible are normally pretty reliable, but nothing’s perfect. A loss of signal, happens more often than you might think.

Alexandria: There are times we know that they're going to be in a dead zone for maybe two or three minutes.

Alexandria: It's just that their signal, because of the speed they're moving and before it's able to get to the next satellite, it's too much of a distance, then that would cause a dead zone to happen. That would cause their signal not to reach us.

Peggy says that getting a brief moment of radio silence isn’t always such a bad thing.

Peggy: Sometimes it's a relief [laughs].

But when you’re outside the ship doing an Extra Vehicular Activity, or an EVA, losing that voice over the headset can be pretty freaky.

[music in]

Peggy: It can be disturbing if you need to have the com. My worst scenario was actually during a spacewalk, and my EVA partner and I could hear each other, and I could hear the crew member that was in the space station, and the ground could hear us, but we couldn't hear the ground.

Typically, losing comms means, “Get back on board until we figure this out.”

Peggy: We would've normally end the EVA because we don't have com, but because Yuri on the station could talk to the ground, we had this kind of relay com going on, which was not going to work for the EVA, but still got us by long enough for the ground to figure out and get the communication systems configured.

[music out]

Talking with astronauts orbiting the Earth at 17,500 miles an hour is hard enough, but as humans go back to the moon, and then to Mars and beyond, communication will be exponentially harder.

[music in]

Paul: Both NASA and private companies like Space X have stated goals to step up lunar missions again, maybe we'll have a permanent lunar base, where crews are rotating in and out on a regular basis.

Paul: That will help us test out and prepare some of the technologies that we need to be able to send astronauts on a two year round trip mission to Mars.

Alexandria: Right now, if we were to go to Mars with the technology that we have, for me saying “Hello” and you saying “Hello” back, round trip, it would be about 40 minutes.

Alexandria: And you just cannot have that, because if something goes wrong while they're there, having to wait 40 minutes just before you can get an answer back is not very helpful at all.

As we head into a new era of space exploration, we’ll need to figure out ways to talk to people on other planets, and maybe, someday, in another solar system. That’s coming up, after the break.

[music out]

MIDROLL

[music in]

In the entirety of human history, we’ve only been able to reach space for 60 years. We’ve barely scratched the surface of this final frontier, and as we journey farther and farther from home, maintaining fast and reliable communication with Earth will be crucial.

Currently, the spacecraft orbiting the Earth are in constant radio communication with ground control [SFX: space comm montage].

These radio waves travel at the speed of light, which is 186 thousand miles per second. That’s fast enough that if we put TDRS satellites around the moon, we could talk to a lunar base with only a tiny bit of lag.

Peggy: If they are able to use TDRS, it would be pretty seamless. There might be a little bit of lag in the communication, just like a second.

[SFX: Testing 1 2 3… Houston, do you read me?]

[music out]

But if you go beyond our moon, real-time communication quickly becomes impossible, even with messages traveling at the speed of light.

Peggy: It's pretty amazing to think that I could be on Mars and say "Houston, I have a problem." And it'll be 40 minutes before they get back and say "What's up?"

NASA is already testing how communication could work for a Mars mission.

[music in]

Peggy: We actually found that something similar to texting is more efficient so that you could text something, go do you other thing, come back when it's convenient and get the answer and continue on.

Texting might work for routine updates and long term planning. But losing the human contact you get from interacting in real time would be a huge adjustment for astronauts on Mars.

Peggy: For psychological reasons obviously that's going to be a big difference, because right now we talk to family and friends. On the weekends we get a video conference. That's not going to happen. It's going to be a one way recorded message both directions, and so it's not like you're going to have a conversation anymore.

[music out]

To make real-time communication possible over such vast distances, we’ll need to be able to send a signal faster than the speed of light. Over the years, science fiction writers have come up with creative ideas for communicating, and travelling faster than lightspeed. One common concept is a wormhole.

Paul: Wormholes are theoretical objects that can act as shortcuts through space. If we had a wormhole, maybe you can just take a couple steps and immediately plant your foot on Mars.

In the movie Interstellar, the crew use a wormhole to jump to distant planets.

[SFX clip: Interstellar clip: “That wormhole lets us travel to other stars. Came along right as we needed it.”

“They’ve put potentially habitable worlds right within our reach.”]

Wormholes have been theorized for decades, but sadly, they’ve never been proven to exist.

Paul: As far as we can tell, we keep trying to cook up actually physical ways of building wormholes or having stable wormholes in our universe. Every time we do it, the universe concocts some reason why they can't exist.

So sending a radio signal through a wormhole to chat with your friend on Mars isn’t very likely.

Paul: If wormholes did exist, yes, you could potentially build one and send a message to Mars very, very quickly. But it looks like our universe doesn't allow wormholes to exist, but we don't know why. And that's a bit perplexing.

Another idea for communicating across space involves something called “quantum entanglement.”

[music in]

Paul: There's this idea in quantum mechanics called entanglement, where I can take two little particles and prepare them in a special way where their inherent quantum properties become mixed together, where in some sense, they're a single quantum object.

If two particles are entangled on the quantum level, knowing something about one particle let’s you reliably predict the state of the other one.

Paul: And this connection persists no matter how far away the particles are from each other. And what this means is that because they share a same state, if I change something about one particle, there will be a corresponding change in the other.

Let’s say you flip one entangled particle upwards. The other particle should theoretically flip up too, even if it’s lightyears away.

Paul: And the initial thought is like, "Oh, I can take that entanglement and I can use communication." Because I can take my little entangled particle and start wiggling it back and forth. And you're saying, "up, up, down, down, down, up, up, up," doing some sort of Morse code. And someone on the other side of the universe can be watching their particle and get the message. It doesn't work that way.

[music out]

The problem is that other forces can affect these particles, too. This would make it almost impossible to distinguish an actual message from random noise.

Paul: The only way I can verify whether this is just random quantum noise or this is a message that I'm getting, is to send a light signal, something that's limited by the speed of light.

Paul: No matter what, the spread of information, the spread of causality, is limited by the speed of light.

Of course, this also makes it really hard to connect with any alien species that might be trying to say hi.

[music in]

Paul: We saw it's 40 minutes round trip just to say hi to Mars, and that's the next nearest planet. A round trip for a “Hello” to our next nearest neighbor star is eight years. And that's just our nearest neighbor. The time and space scales in our galaxy are so incredibly immense and outside the experience of anything that we've ever experienced as a species.

Even sending a normal radio signal to a neighbor star would be pretty challenging. Throughout the universe, there are all kinds of natural reasons that we find radio waves. For instance, a “quasar” is a supermassive black hole surrounded by a giant field of gas. Supermassive blackholes [SFX: black hole rumble] are billions of times more massive than our sun. As the gas [SFX: gas] around a quasar gets pulled into the blackhole [SFX: suction], other particles get blasted [SFX: energy blast] outwards as electromagnetic radiation.

Much of this energy registers as visible light, making quasars some of the brightest objects in the universe. But some quasars also emit powerful radio waves. In fact, when astronomers first observed these objects using radio telescopes, they called them “quasi-stellar radio sources,” which was eventually shortened to “quasar.”

Because of all of the galactic radio noise made by quasars, sunspots, and even Jupiter’s ionosphere, any interstellar message we tried to send would get garbled pretty quickly.

Paul: Our own radio [SFX: Music fade out and white noise fade in] messages that we’ve blasted into the cosmos are just mixed with the general radio background. You can't even hear us from our nearest neighbor star, because we're not powerful enough.

So if any alien civilizations are out there listening, they probably can’t hear us.

Paul: We're not alone in the universe, but we might as well be.

[SFX: white noise out]

[music in]

While the challenges ahead may seem daunting, it’s these same challenges that will inspire future generations of space explorers.

Peggy: I was nine years old when the Apollo 11 landed on the moon and I thought, “Wow, cool job. I’d like to do that.” Of course, when you're nine, you want to do lots of things but it was one that stuck with me.

As long as curious people keep looking to the stars and wondering what’s out there, we’re going to keep chasing the next horizon.

Paul: I just love the magnitude, the timescales, the space scales. We get to watch stars being born and watch stars die. We get to watch galaxies collide. We get to watch the universe expand before our very eyes. This is stuff so far beyond our normal everyday Earthly experiences. It just draws me in every single time.

Twenty Thousand Hertz is hosted by me, Dallas Taylor, and produced out of the sound design studios of Defacto Sound. Find out more at defactosound.com.

This episode was written and produced by Jack Higgins. And me, Dallas Taylor. With help from Sam Schneble. It was story edited by Casey Emmerling. It was sound designed, and mixed by Soren Begin and Jai Berger.

Thanks to our guests Alexandria Perryman, Peggy Whitson and Paul Sutter.

Paul hosts a really cool podcast called Ask a Spaceman, which you can find right here in your podcast player.

Thanks to the team at NASA who make all of their audio and communications public, and thanks to the National Archives in DC.

Thanks to listener Dan Ray for coming up with the title for this episode. If you’d like to help us name episodes, and get bonus content like sneak previews and goofy sound design videos, then be sure to follow 20K on Facebook and Twitter, and subscribe to our subreddit, Reddit dot com slash R slash 20K.

Thanks for listening.

[music out]

Recent Episodes

VIEW ARCHIVE

Sonic Utopia: Can we build a better sounding world?

Art by Matthew Fleming.

This episode was written and produced by Casey Emmerling.

Technology has the power to transform the way our world sounds. It could even give us entirely new ways to experience our surroundings. In this episode, we explore the sounds of the future, and how we can use the tools we already have to build a better sounding world. Featuring Rose Eveleth, Creator and Host of the podcast Flash Forward, Acoustician Andrew Pyzdek, and Architect Chris Downey.


MUSIC FEATURED IN THIS EPISODE

Wanderer by Makeup and Vanity Set
1:57 AM (The Green Kingdom Remix) by Hotel Neon
Wide Eyed Wonder by Dustin Lau
June by Uncle Skeleton
Rubber Robot by Sound of Picture
Lick Stick by Nursery
Stuck Dream by Sound of Picture
Springtime by Sound of Picture
Drawing Mazes by Sound of Picture
Dark Matter by Sound of Picture
Brackish Water by Alistair Sung
About You (No Oohs and Ahs) by Vesky
Trek by Sound of Picture
Gimme Gimme - Instrumental by Johnny Stimson

Twenty Thousand Hertz is produced out of the studios of Defacto Sound and hosted by Dallas Taylor.

Follow Dallas on Instagram, TikTok, YouTube and LinkedIn.

Join our community on Reddit and follow us on Facebook.

Become a monthly contributor at 20k.org/donate.

If you know what this week's mystery sound is, tell us at mystery.20k.org.

To get your 20K referral link and earn rewards, visit 20k.org/refer.

Discover more at lexus.com/curiosity.

Subscribe to Flash Forward wherever you get your podcasts.

View Transcript ▶︎

You’re listening to Twenty Thousand Hertz. I’m Dallas Taylor.

[music in]

In our busy modern lives, it’s not often that we stop and really think about what we hear.

[SFX: Alarm, car start, city ambience, train, office ambience]

Most of the time, we just accept these human-made sounds without a second thought. But it’s important to remember that our world didn’t always sound this way. Matter of fact, the sound of our world changes constantly. Our cities and towns sound completely different now than they did fifty or a hundred years ago.

[SFX: Horse, old timey, car horn, klaxon, car pass by]

So what will our cities and towns sound like fifty… or even a hundred years from now? What if we could collectively sound design our world? What would that sonic utopia be like, and how can we get there?

[music out]

In our future sonic utopia, there will certainly be sounds we want to remove.

Rose: The first thing that comes to mind is the screech of the New York City subway, [SFX] which is incredibly loud and is sort of emblematic of the lack of updating of that city's infrastructure.

That’s Rose Eveleth.

Rose: I'm the creator and host of a podcast called Flash Forward, which is all about the future.

[music in]

[SFX: Subway train screeching as Rose describes it]

Rose: I love New York. But standing on the one train platform and the train rolls in [SFX] and you really feel like you're being stabbed in the ear.

We all know that loud noises can cause hearing loss, but that’s just the tip of the iceberg. When we’re exposed to loud noise, our bodies release stress hormones. These hormones raise our blood pressure, which contributes to heart disease and Type 2 diabetes. Studies have even shown that kids who go to school in louder areas tend to have more behavioral problems, and also tend to skew worse on tests.

Rose: We know that constant sound like that has real impacts on learning, on people's ability to retain information.

[music out]

To be clear, this train problem goes way beyond the New York City subway. Anytime you have a heavy metal object moving along a metal track, like a subway, or a train, you’re probably going to end up with some screeching. But what if, in the future, that subway or train car wasn’t even touching the track?

[music in]

In recent years, some countries have begun building “maglev” trains, which is short for “magnetic levitation.” A maglev train doesn’t have a conventional engine. Instead, it uses powerful electromagnets to stay suspended above the track.

[SFX: Maglev train]

When it’s suspended, another set of magnets propel it forward.

Andrew: They don't have rails that they're rolling along physically.

That’s acoustician Andew Pyzdek.

Andrew: They're basically floating on a cushion of air, so they can be very, very quiet.

Maglev trains aren’t just quieter than normal ones, they’re also smoother and faster. The highest speed recorded on a maglev train was 373 miles an hour.4 As maglev trains replace normal ones, we can expect to hear less of this [SFX: Normal train] and more of this [SFX: Fast maglev].

[music out]

That’s a great start, but what about cars? As you may already know, electric cars can be extremely quiet. [SFX: Low-speed electric car]

Andrew: Obviously they're quieter, but most importantly at low speeds where the engine noise is the loudest thing.

As electric vehicles become more common, areas with low-speed traffic will quiet down quite a bit. But once you get on the freeway, even an electric engine doesn’t help that much.

Andrew: At high speeds on the freeway, most of the noise actually comes from the tires. [SFX: Car pass by] So the advancements that you can expect to improve roadway noise are… with the composition of the roads themselves.

In 2007, researchers developed a new paving method called Next Generation Concrete Surfaces.2 Roads that are paved this way are up to 10 decibels quieter than normal ones. That’s the difference between this [SFX: Busy freeway] and this [SFX: Busy freeway by -10bd quieter].

Andrew: As we improve infrastructure and replace old roads with new roads that are made to be quieter, we can see those freeways becoming less noisy.

[music in]

When it comes to transportation, our sonic utopia is sounding a lot quieter. But of course, people aren’t the only things being carried around in cars and trains. There’s also all of our stuff. Amazon currently ships over 6 million packages a day.6 As populations increase and countries develop, there will be an even bigger demand for quick delivery. And the latest idea to handle that demand is delivery by drone.

[music out]

Now, commercial drone delivery hasn’t taken off quite yet, but both Google and Amazon are working on changing that. Here’s a clip from a video that was made by Amazon:

[SFX Clip: “Amazon: Here’s how it works: Moments after receiving the order, an electrically powered Amazon drone makes its way down an automated track, and then rises into the sky with the customer’s package on board. Cruising quietly below 400 feet, carrying packages up to 5 pounds…”]

Amazon describes these drones as “quiet,” but in their videos, they never include the actual audio of flying drones. That’s probably because drones really aren’t that quiet. Even the small ones that hobbyists buy can be pretty loud. [SFX: drone]

If drone delivery becomes common, things could get really loud, really fast. Imagine a crowded city with hundreds of delivery drones buzzing by at all times. [SFX: Sparse drones]

Now imagine how bad it would be near the fulfillment center, where the drones actually take off and land. [SFX: Heavy drones]

This is not very utopian. But, thanks to nature, there may be ways of making drones quieter.

Andrew: There's some work that's been done looking at owls and the way that their feathers are shaped in order to reduce noise. So the edge of an owl's feather is very ragged. The feathers themselves are kind of loose and wavy. And that's why they're such stealthy fliers because their feathers aren't rigid.

For instance, barn owls fly so quietly that humans can’t hear them until they’re about 3 feet away.

Andrew: The exact opposite of that is a pigeon. And every time they take off, that pigeon sound, [SFX: Pigeon] some people think that it's a vocalization that the pigeons are making. That's the sound of their feathers vibrating as they flap their wings.

The recording of the pigeon you just heard is from a BBC special about owls. In the special, they recorded a pigeon, a hawk and an owl flying over a set of microphones. Here’s the pigeon again: [SFX: Pigeon] Here’s the hawk: [SFX: Hawk]

And here’s the owl: [SFX: Owl]

Did you catch that? Neither did I. Here it is again, turned up twice as loud: [SFX: Owl]

Inspired by owls, researchers are already exploring ways of making airplanes quieter.

[SFX: Airplane]

Like a car on a freeway, a lot of the noise from a passing plane comes from air flowing around the plane. One way of reducing that noise would be to make the plane’s wings more like owls’ wings. This could be done by adding more flexible, porous materials to the edges of the wings. Theoretically, something similar might be possible with drones.

Andrew: I think that if drones start being a more everyday part of our lives, that there will be a pretty strong pressure to make those drones be a little bit less annoying to listen to.
 [music in]

So far, we’ve turned down the volume on future cars, trains, planes and drones. Not too shabby. But what does our sonic future sound like if you’re getting around on foot? Something that might become common is targeted audio messages that you can hear as you walk down the street. When audio is beamed to a small, specific area, it’s called an “acoustic spotlight.” These are already found in many museums.

Andrew: Say if you were looking at a painting, you might hear sounds that remind you of the space and the painting.

For instance, you may walk up to a painting of a peaceful landscape, and hear this

[music out]

[SFX: birds, light wind, blowing grass].

Andrew: And the technologies that are used to make these acoustic spotlights can range from very simple: There's parabolic microphones, where you have just a plastic shell around a normal speaker. And as that speaker generates sound, it focuses it downwards towards the person standing under the spotlight.

But acoustic spotlights can also be made with ultrasound.

[music in]

Andrew: Ultrasound is very amazing. Ultrasound is sound. It's not something different. It's just sound that's at a frequency above what people can hear.

The normal range of human hearing is from about twenty hertz to twenty thousand hertz [SFX: Sine wave of 20 hertz sliding up to 20,000 hertz]. Anything above 20,000 hertz is considered ultrasound. Making an acoustic spotlight with ultrasound involves something called a “parametric array.”

Andrew: So parametric arrays are basically you have two beams of ultrasound that you make intersect with each other. And at the point where they intersect, they create audible sound.

[music out]

A parametric array is almost like a sonic laser that lets you beam a sound message to a very precise spot [SFX: VO shifting around like it’s looking for a target]. If advertisers started doing this, it could get out of hand pretty quickly. Imagine you’re walking downtown in a crowded city. [SFX: Times Square ambience]

Every time you pass by a billboard or a store or a restaurant, you hear a little commercial or jingle. [SFX: Walmart] [SFX: McDonalds] [SFX: New in theaters] [SFX: Parasitic infection] [SFX: Pringles]

That’s definitely not what I want in my utopia. But audio aimed at your location doesn’t have to be a bad thing. For instance, rather than just playing the sound out in the open, the signals could be beamed to a device, like a specialized headset. That way, you could choose whether or not to tune in.

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Rose: I think in my utopia people would be able to kind of customize their experience to themselves. I could make the world feel safe and happy and lovely wherever I am and that might look different from somebody else. And I don't know if that means special things that go in my ear that kind of like filter in and out the sounds that are important or not. Or whether that means high-tech technology that only beams aural information to certain people who have their profile set up to be like maximum sound versus minimum sound, or whatever it is.

Rose: And you can kind of choose to customize your experience of the world that way.

In the future, headphones and earbuds won’t just be headphones and earbuds. They’ll be much more integrated. We already have noise reduction, but future hearing wearables may have selective noise reduction. They may filter out unpleasant sounds, or reduce dangerous volume levels. They may even have corrective hearing loss algorithms built in… like a merger of current hearing aids, noise protection, and traditional earbuds.

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With geolocation targeting, these headsets could give you extra information about your surroundings, without the visual distraction of smart glasses. Imagine kind of an audio tour of the entire world. This might even help people build more of a connection with their community.

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Rose: I think that there is a space for like, a sort of community audio project where you could have this living audio document that is kind of like a museum tour, but for your own space.

Rose: So you could be walking down your street and you could hear a story from your neighbor about something.

Rose: It's maybe the person who's lived on that block for 30 years being like, "You might not know this, but here's an interesting piece of history about where you're from." Or, you know "Hey, there's a city council meeting today. Maybe consider going to it."

Rose: Just little things like that where you could constantly be keeping up with your neighbors or understanding what the needs are in the community.

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A hightech headset that you wear all the time could also be a game-changer when it comes to real-time translation. If every word you hear gets instantly translated into your native language...

Andrew: People can talk to other people speaking a different language and not have that language barrier. There's already quite a bit of work happening there, and that will continue to move forward.

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New technology could positively change how our cities, neighborhoods, and homes sound. It could even give us entirely new ways to experience our surroundings. But we have to put in the time and effort if we actually want our future to sound better. To get some perspective, it’s helpful to talk to someone who really understands how important sound is to the spaces we design. Maybe someone like an architect… who’s also blind. That’s coming up, after the break.

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MIDROLL

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From acoustic spotlights to swarms of retail drones, there’s all kinds of technology that’s likely to affect the sound of our future. But as we build that future, we have to ask ourselves… What kind of sonic environments do we want to create?

The spaces we design should be acoustically functional. In other words, the acoustics of a building should support whatever goes on in that building. But it’s about more than just utility. We also want the places we spend time in to just sound good.

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That’s easier said than done, and too often, people just don’t think about it.

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Chris: Sound is so often just left to be accidental.

That’s Chris Downey.

Chris: I'm an architect located in Piedmont, California just outside of Oakland.

As far as architects go, Chris has a pretty unique background. In 2008, he was having some trouble seeing clearly. An MRI scan revealed a brain tumor right against his optic nerve. Fortunately, doctors were able to remove the tumor through surgery. But two days after the procedure, Chris’ vision started to fail. After three days, he was blind.

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Of course, adjusting to life without sight took time. But Chris didn’t let blindness stop him from doing what he loves. In fact, he says that losing his sight has actually been helpful to his understanding of architecture.

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Chris: Losing my sight, as an architect, has really benefited my work by really getting me back in touch with the human bodily experience of being in the space at any given moment in time.

Chris: The sound of the space. The acoustic soundscape of the architecture [SFX: footsteps] as you move through it dynamically, hearing it as you move through and really listening to the architecture.

The choices that are made when a building is designed have a massive impact on what it’s going to sound like. Sometimes, these choices are very deliberate, like the way concert halls are designed to amplify and enhance the sound of an orchestra.

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A lot of the time, though, it can be hard to predict exactly what a building is going to end up sounding like.

Chris: It's so hard to draw or model sound. How do you do that? As architects, we can't do that. If we talk with an acoustic engineer, they might be able to give us all sorts of scientific representations of things. But unless you're a highly trained acoustic engineer, it means nothing.

Most of the time, you won’t really know until the building is finished.

Chris: And then it’s built. It's really too late.

At that point, you might not be happy with the result. Maybe you’ve had the experience of trying to study in a library where every little noise echoes off the walls. [SFX: Library ambience with heavy verb]

One way to prevent this is to digitally emulate what a space might sound like, while it’s still being designed.

Chris: There's been a really interesting collaboration I've had with some acoustic designers that have a sound lab that they use to model sound. They use it really to anticipate and demonstrate the sound of a music hall or some other very, sort of, acoustically intentional space.

Using this technology, you can input the dimensions and other aspects of a building you’re designing. Then, the computer can emulate what a voice... [SFX: Voice with room verb] or an instrument... [SFX: Saxophone with same room verb] or a footstep… [SFX: Footstep with room verb] is going to sound like inside that space.

[SFX: Over Chris’ next line we hear those same sounds with evolving room verbs]

Chris: You can tune it. You can test it, just as we do visually with drawings and models and photorealistic computer-aided renderings and things, it's doing the same thing with sound.

Chris: We started working with that for me to anticipate the dynamics of sound as you move through a space, so they put my cane tapping inside the digital space [SFX: Cane tapping] and then we hear what it's like to hear the architecture as you move through, and anticipate that, so that I can really design intentionally

Acoustic modeling technology isn’t universal yet, but some designers have started taking acoustics more seriously.

[SFX: Noisy airport sounds]

Airports are notoriously noisy, and all of that noise can make traveling even more stressful than needs to be. But many airports have started installing noise absorbing materials to help keep people calm. The next time you’re in a new terminal that feels unusually quiet, look up at the ceiling. Oftentimes, you’ll see very unique looking tiles. These tiles can be subtle enough to fit right in with the architecture, and they make a huge difference in sound quality.

Unfortunately, though, when it comes to noise, restaurants are still way behind. We’ve all had the experience of being in a restaurant that’s just uncomfortably loud. [SFX: Crowded restaurant gradually getting louder; chatter, silverware clinking]

Chris: There are environments in restaurants that the soundscape becomes really problematic.

Since Chris is blind, he can’t read someone’s lips or pick up cues through their facial expressions.

Chris: So I'm absolutely dependent on the acoustic environment to communicate. And some of these environments are so loud, it's just so exhausting to try to hear, that within 15 minutes, I'm done. I'm exhausted. I’ve had enough. [SFX: Restaurant sounds out] And in sharing that with other people, people with hearing impairments, they have the same experience, and it could be because of a hearing aid that the sound is very different, and it becomes nauseating.

Accessibility laws and city codes are the reason we have helpful sounds at crosswalks, [SFX] and ramps for wheelchairs. And while the US government does regulate how much noise workers should be exposed to, those codes are rarely enforced in places like restaurants and shops.

Chris: Our codes don't really deal with that, so I think that there's some more wisdom and more research and development that needs to come into creating safe environments in places like that.

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We used to talk about second hand smoke in bars. Well, you know, what's that acoustic environment doing to the health of the people that work in those environments?

Whether it’s noisy restaurants or noisy freeways, it’s easy to imagine that a quieter future would be a better future.

Andrew: I think that we kind of want silence more than we get it. And that's really what it comes down to is that we live in a very loud world. [SFX: Loud city montage] Finding silence is very difficult unless you live in a place that's already pretty quiet. So I can understand why the focus on making the world sound better is to make the world sound less. Because it sometimes feels like there's just too much vying for our attention.

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If I had a giant audio board for the world, I’d pull the fader down on most of what’s human made. Our brains love the sound of nature, and it would be great to get competing sounds out of the way. However, that doesn’t mean that all human made sounds should be lost.

Chris: There's been a lot of effort going into sound masking, masking of the sound in an environment, which from the blind experience isn't necessarily a good thing, because in masking the environment, we're losing some of the necessary sound. We need to hear the environment.

For instance, making cars completely silent could be dangerous.

Rose: I mean, I think many people probably have the experience of almost being hit by a Prius in a parking lot because you didn't notice it there because it doesn't make any sounds.

Chris: I've experienced new electric buses that are so quiet it's hard to even know they're there. I've had one that pulled up right in front of me when I'm standing at the sidewalk, and I didn't hear it approach and I kind of sensed there was something in front of me, and I reached up to find there was a bus there just a couple inches in front of my face. [SFX: Bus pulls away] And that was terrifying. So in trying to remove sounds and make some of these things quiet, you have to be careful about maintaining some necessary sound for safety.

All of this can feel overwhelming, but there are things you can do to make your surroundings sound a little better. The first step is to really hear your environment. To do that, you’ll need to make it as quiet as possible.

[SFX: Subtle HVAC sounds]

Andrew: Try powering off your house. Go to the breaker, cut off the power. [SFX: Power down, HVAC off] Assuming that that's not going to damage anything, turn off any sensitive electronics first that might get hurt by a brownout. But you can flip the breaker and hear how different your house sounds when there's nothing on. And then when you turn those individual breakers on, you'll notice right away. [SFX: Click + fridge] "That's what my refrigerator sounds like." Or, [SFX: Click + AC] "Wow, I didn't realize our AC unit was that loud." You usually don't notice these things until they're gone and they come back.

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Most of us can’t just go buy a quiet new AC unit, but this can still be a good exercise to help you notice the sounds that you may have been ignoring. Maybe you can power down that video game system all the way, rather than leaving it in sleep mode with the fan running. Maybe it’s time to put some WD-40 on that squeaky closet door. Maybe you can find a tapestry to hang in your living room. Soft surfaces are a friend to good sounding environments.

Maybe you could also write a friendly email to that restaurant that you’d love to go back to, if it wasn’t quite so loud. Or maybe you can write a letter to your mayor, or your representatives, and tell them how the screeching bus brakes wake your whole building up at 6:30 in the morning. The point is, even a little sonic change goes a long way. And if enough people start doing this, our future will sound better.

Chris: Sound can affect us on a subliminal level and it can set a mood it can make us struggle. It can put us at ease. So, I think it's a sense that we really need to pay a lot more attention to, to really add to the quality of our living experience, in whatever setting we're in.

Andrew: There's a lot that can happen right now that would be possible if people just were willing to do it.

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Twenty Thousand Hertz is hosted by me, Dallas Taylor, and produced out of the sound design studios of Defacto Sound. Find out more at defactosound.com.

This episode was written and produced by Casey Emmerling, and me, Dallas Taylor. With help from Sam Schneble. It was edited and sound designed by Soren Begin, Joel Boyter, and Colin DeVarney.

Special thanks to our guests: Rose Eveleth, Andrew Pyzdeck and Chris Downey. Rose’s podcast Flash Forward is one of my favorites, it’s all about the possible and not so possible futures. You should definitely go subscribe. You can also find articles by Andrew at acousticstoday.org. And you can learn more about Chris’ work at arch4blind.com. That’s A-R-C-H, the number 4, blind dot com.

If there’s a show topic that you are dying to hear, you can tell us in tons of different ways. My favorite way is by writing a review. In that review, tap 5 stars and then give us your show idea. And even if you don’t have a show idea… I’d love for you to give us a quick 5 star rating anyway. Finally, you can always get in touch on Twitter, Facebook, Reddit, or by writing hi@20k.org.

Thanks for listening.

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