KRVS

He'll Retune Your Living Room

Jun 21, 2012
Originally published on June 21, 2012 5:11 pm

Want better sound from your home music system? Electrical engineering professor Chris Kyriakakis says it might not be your stereo components that are the problem — it might be your home.

Kyriakakis, who is the principal investigator at the Immersive Audio Lab at the University of Southern California, has spent years figuring out how to make the experience of listening to recorded sound as close to what you hear in a live performance as possible.

"[The] first problem that we started looking at," he says, "had to do with figuring out how sound, when it leaves the loudspeaker — how does it interact with the environment, and what can go wrong?"

Many things, he's found. But Kyriakakis has developed software that will fix most of them in real time, before the problems get to your ears. Say there's something about your living room that makes whatever you're listening to sound muddy; his software will clear it up.

"A lot of sound from the speaker comes to your ears, but a lot of it goes to other places where it's not supposed to, hits the walls and the floors and the ceilings and then arrives at your ears. That's a form of distortion. It's called room distortion," says Kyriakakis. "We set out to figure out — first of all — how to measure it, how to quantify it, and then is there something we can do about it to fix those kind of problems."

Another problem a lot of people hear every day: poor sound quality on mobile devices, like tablet computers. You can't turn them up very loud because the speakers are so small, bad things happen at high volume.

"You start to hear some crackles and pops," he says. "And that gets really bad. And so to stop that, they just limit that to this maximum loudness. But if we turn on our technology, we can catch those crackles and pops before they come out." And if you turn on their technology, you can turn the volume up twice as loud as you ordinarily can on a tablet.

Kyriakakis has also made software to make cellphones and earbuds sound better. Those aren't available now, but he expects they will be by Christmas.

About 10 years ago, he co-founded a company called Audyssey that manufactures components, including one that compensates for the undesirable acoustics in your living room. Audyssey also licenses its software to makers of stereo receivers, televisions, home theaters, Imax theaters and high-end European automobiles.

His field is called psychoacoustics. It's not just about measuring sound, but about how we perceive it. For one thing, our bodies have evolved to screen out low frequencies, or bass sounds, at low volumes for good reason. If we didn't, says Kyriakakis, "you'd be hearing, first of all, your blood flow. Your heart thumping. Other organs making noise."

That's why, when you listen to music at low volume you can't hear the bass. He's developed software that can put the bass back in, even when you've got your music turned down.

Kyriakakis has been at it since 1996, when the National Science Foundation funded research into immersive technologies, sometimes called virtual reality. His quest started with real reality: Boston Symphony Hall, known for its great acoustics. He put microphones all over it and measured the ways the sound reflected off the walls and floor and different parts of the room.

"And then we used those differences to simulate what the effect of reflections would be in recordings that didn't have the luxury of being recorded in that space with that many microphones." Kyriakakis says that even the little curves of your ear affect the way you perceive sound, so he measured those too.

All that detail work has paid off — in your house, your car and your computer.

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ROBERT SIEGEL, HOST:

From NPR News, this is ALL THINGS CONSIDERED. I'm Robert Siegel.

MELISSA BLOCK, HOST:

And I'm Melissa Block. If you're listening to our program on your car radio, the sound quality may not be ideal. But you're about to meet a man who can do something about that. He's Chris Kyriakakis, at the University of Southern California's Immersive Audio Lab. He's spent years trying to make the experience of recorded sound as close to the live performance as possible; in your house, your car, or on your computer.

NPR's Ina Jaffe has the latest entry in our series on "West Coast Innovators."

INA JAFFE, BYLINE: Want better sound from your home music system? Electrical engineering professor Chris Kyriakakis says it might not be your stereo components that are the problem. It might be your home.

CHRIS KYRIAKAKIS: The first problem that we started looking at had to do with figuring out how sound, when it leaves a loudspeaker - how does it interact with the environment, and what can go wrong?

JAFFE: Oh, so many things. But Kyriakakis has developed software that'll fix most of them in real time, before the problems get to your ears. For instance, let's say there is something about your living room that makes this Joan Osborne cut sound muddy. But listen carefully, and you'll quickly hear the software clear it up.

(SOUNDBITE OF SONG, "HEAT WAVE")

KYRIAKAKIS: A lot of sound from the speaker comes to your ears. But a lot of it goes other places, where it's not supposed to; hits the walls and the floors and the ceiling, and then arrives at your ears. And that's a form of distortion; it's called room distortion. And so we set out to figure out, first of all, how to measure it, and how to quantify it. And then, is there something we can do about it to fix those kinds of problems?

JAFFE: He's been at it since 1996, when the National Science Foundation funded research into immersive technologies, sometimes called virtual reality. His quest started with real reality - Boston Symphony Hall, known for its great acoustics. Kyriakakis put microphones all over it, and measured the sound reflections in different parts of the room.

KYRIAKAKIS: And then we used those differences to simulate what the effective reflections would be in recordings that didn't have the luxury of being recorded in that space, with that many microphones.

JAFFE: Kyriakakis says that even the little curves of your ear affect the way you perceive sound. So he measured that, too.

KYRIAKAKIS: If you put miniature microphones in willing subjects, it's totally painless.

JAFFE: Kyriakakis works in a field called psychoacoustics. It's not just about measuring sound, but about how we perceive sound. For instance, our bodies have evolved to screen out low frequencies or bass sounds at low volumes - and for good reason.

KYRIAKAKIS: You would be hearing, first of all, your inner - your blood flow, your heart thumping, other organs making noise. Those are all very low frequency.

JAFFE: So let's say that the neighbors tell you to turn down that Joan Osborne cut.

(SOUNDBITE OF SONG, "HEAT WAVE")

JAFFE: The bass just disappears. Kyriakakis has developed software that'll put it back, but you might not be able to hear it on the radio. The software that was developed in the lab hasn't stayed there. About 10 years ago, Kyriakakis co-founded a company - called Audyssey - that manufactures components, like one that compensates for your acoustically challenged living room. Audyssey also licenses its software, so you may have heard it at the local IMax theater. Or it might be in your TV or stereo receiver, or your Jaguar.

The current challenge is mobile devices; tablet computers, for instance. You can't play them very loud because the speakers are so small, bad things will happen. For example, to this Dire Straits cut.

KYRIAKAKIS: You start to hear some crackles and pops.

(SOUNDBITE OF SONG, "SULTANS OF SWING")

KYRIAKAKIS: And then it gets really bad and so to stop that, they just limit it to this maximum loudness. But if we turn on our technology, we can catch those crackles and pops before they come out.

(SOUNDBITE OF SONG, "SULTANS OF SWING")

JAFFE: That's twice the volume you can ordinarily get from a tablet computer. Kyriakakis has also made software to make cellphones and ear buds sound better. Those aren't available now, but he expects they will be by Christmas.

Ina Jaffe, NPR News. Transcript provided by NPR, Copyright NPR.