Dec 28, 2012

Ears don't lie

We humans are visual creatures. But maybe we should reconsider.

"Eyes lie," says auditory neuroscientist Seth Horowitz. "But the ears don't."

Horowitz's field of study -- how sound rattles around in our brain -- is fascinating. A short run-in with him before Christmas has me knee-deep in auditory explorations: repetitive tones, videos of kids in music class, and a raft of Google searches.

According to Horowitz, our auditory-bending brain may be one of the best things we have going for us. I mean, he's pretty biased (Horowitz is the author of the new book, “The Universal Sense: How Hearing Shapes the Mind") -- but seeing him speak at New York City's The Museum of Modern Art, I was pretty blown away by what I was hearing about hearing. And I thought, hey, the holidays are here, you've probably either run out of one-liners to see you through another get-together and could use a little cocktail party science top-up, or you're itching for some fake excuse to sneak away from all the family time for a minute (e.g., "Hey, ma, I'll be right there, I just need to check in with, um… work?!")

So, I invite you to plumb… not the depths of our sense of hearing... because, let's face it -- I'm not going that deep. But here are some tidbits to see you through until we have a for-real, actual sit-down with Horowitz (and/or, I finish his book). Which is good, as it gives y'all time to send in questions about sound and the brain. (And to listen to our shows on Pop Music and Musical Language.)

Speed of sound:

Hearing is our fastest sense. (Who knew?!) Horowitz says that it takes our brain at least one-quarter of a second to process visual recognition. But sound? You can recognize a sound in 0.05 seconds. And our brain is so adept at hearing the differences between sounds, we can sense changes of sound that occur in "less than a millionth of a second," according to Horowitz's book. Why this need for auditory speed? It's our evolutionarily-shaped emergency response system. It let our ancestors hear a twig snap in the woods at night, when all was supposed to be quiet and they couldn't see. Yet, for most of us, we're wired to tune out non-essential sound, so the world doesn't feel like a sensory overload.

Honest ears:

Remember optical illusions, those eyeball oddities that make it appear like circles are moving and vases are faces? It turns out, there are no auditory illusions in nature (that's how honest our ears are, you can't trick 'em), says Horowitz. Instead, any audio paradoxes you hear are created by technology, and there are only 10 by his counting. One he played for us is known as "the shepard tones." Have a listen, and then we'll explain it:


In this series, created by electronic composer Jean-Claude Risset, the tones seem to be continually ascending in pitch when in fact… it's the same series of tones, being played in a loop; and that loop always ends up where it started. It's like an auditory version of the famous Escher stairs painting. Now, I don't yet know how this works (not sure what it does to mess with the brain, but if you do, let us know); so for now let's just settle into the fact that it's crazy.

When diving into the internet world of audio paradoxes, I came across one that Horowitz didn't play for the crowd. It's less of a paradox, and more of a technique. A mind-blowing technique. When the video below started, I flipped over my right shoulder to see if someone had opened the door to come into the room (I wasn't in a room, there was no door). Have a listen, and make sure you're wearing headphones (there are actually no visuals, so close your eyes to make it even better):


As they said in the audio, they created this sound by sticking microphones in a dummy's head. Making it sound like it was in your head. Weird.

Sleepy sounding:

Did you know that when you are in a bar, all the noise -- the clash of glasses, yell of a bartender, and couple fighting in the corner; the jokes of friends, slam of the door, and music jamming from the jukebox -- activates our body's flight or fight system? In response to that, the body wants to do something, anything, to manage the adrenaline that's pumping through its veins. In this case, that means spend money. Eat more. Get another round. Well, Horowitz and his team are interested in this and other ways our body reacts to sound. Specifically, they are interested in understanding how sounds make us feel, then isolating sounds that make us feel a certain way and putting them to use.

So, among others, his team is looking into the sounds that: help us concentrate, make us feel nauseous, and put us to sleep. His thought is not to use them in a Big Brother sort of way (imagine a store with the ability to play tracks that make us buy, buy, buy!) but to, say, help a student perform better on a test. Or help a journalist concentrate in the midst of a bustling news room. In fact, he's already released a sleep CD, wherein low-frequency recordings are overlaid onto classical music. And these low-frequency sounds are often inaudible -- it's not about us hearing them, it's about our brain doing so; it's about how they turn on the brain. For example, one of the low sounds on the CD activates the same area of the brain that is pinged when riding in the back of the car on a long trip, when you just can't help but fall asleep. (Turns out, writes Horowitz, falling asleep in cars, even when it's important for you to stay awake, is actually another form of motion sickness, called Sopite syndrome.)

Sound that puts you to sleep, sounds that go bump in the night, and sounds that don't lie -- you see why I can't stop thinking about my ears? But if it's not enough, I'll leave you with this: you can thank Horowitz the next time the T-Mobile ringtone interrupts your movie date -- he and his team created this addictive jingle using a computer algorithm based on four notes, inspired by the grey squares and pink T of the T-Mobile logo.



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