DAVID GREENE, HOST:
On MORNING EDITION, we've been exploring the scientific art of close listening, decoding nature through sound. Today, NPR's Christopher Joyce and audio producer Bill McQuay of the Cornell Lab of Ornithology bring us this story of Christopher Clark. Clark revealed how human-made noise is blanketing the ocean and making it harder for marine animals to hear their own world.
CHRISTOPHER JOYCE, BYLINE: In 1972, Christopher Clark was an engineering student in college. He met Roger Payne. Payne and his wife, Katy, were the first biologists to discover that whales sang. The Paynes needed someone with engineering skills to record whales in Patagonia, Argentina. Chris said, sure, sounds like fun.
CHRISTOPHER CLARK: We were living in tents, getting blown around in Patagonia on a beach. To me, it was like, someone pays this guy to do this? I had Magellanic penguins in my tent stealing things.
(SOUNDBITE OF PENGUINS)
JOYCE: They'd go to the beach every day and drop a hydrophone, an underwater microphone, into the ocean. They could hear the whales calling, and they could see them on the surface. But they had a frustrating problem.
CLARK: But you don't know who's making the sound. It's like dropping a microphone into Central Park. So the question was, hey, Chris, can you figure out a way that you can tell which whale is making the sound?
BILL MCQUAY: Clark had an idea. What if he put three hydrophones in the water, spaced them maybe a half a mile apart? The order in which the hydrophones picked up the sound would indicate the location of the whale they were listening to. It's the same way your two ears work. The lag time in reaching one ear to the next gives you a sense of where the sound comes from.
CLARK: So suddenly, it was like, oh, now I can start putting the picture together of who's saying what when and what's going on. And so you're eavesdropping. What's going on in this society here?
JOYCE: Clark became a pioneer in the emerging field of bioacoustics, studying the sounds of animals. He says he'd been a good listener since he was a choir boy singing at St. John the Divine Cathedral in New York City.
MCQUAY: But instead of human voices, now he wanted to hear what the whales could do. There were lots in the Arctic, so he went to Point Barrow, the northern tip of Alaska.
CLARK: It's minus 30 degrees out. You're bundled up. You have complete sensory deprivation. Your nose is frozen. Your eyes are covered, right? It's all gray-white, bleached out, right? You're bundled up, and you lower the hydrophone into the ocean.
And you hear this. It's just like - it's a complete cacophony of voices and singers. And you're going, oh, my God, it's like I just went into a complete twilight zone or something. I'm in a completely different world.
(SOUNDBITE OF WHALES)
CLARK: Belugas and bowheads and beardeds and you're going, oh, my God, it's a jungle underneath the ice. And I'm getting all excited about this.
JOYCE: Although he soon realized that he wasn't the first person to hear all this. When he gave his earphones to a local Eskimo to listen, the Eskimo already knew those sounds.
CLARK: In their culture, they put the end of the oar up against their jaw, put the paddle into the water, and they listen.
JOYCE: But hydrophones gave much more clarity, and he could record the sounds.
MCQUAY: So he compiled an archive of whale sounds that biologists were eager to analyze. Then, a chance encounter made him realize that he'd only had a tiny glimpse of what was going on in the oceans.
JOYCE: On a plane flight back from Alaska, he met a Navy captain who knew all about hydrophones.
MCQUAY: Small world, Clark thought. So they had lots to talk about.
JOYCE: But that was it, right?
MCQUAY: Yeah, they didn't talk again for years.
JOYCE: Then one day, Clark got a phone call. Would he like to spend a day at a Naval office in Virginia listening to their hydrophones - not recordings, but live audio straight from the ocean?
CLARK: Something I'd heard about as sort of a whisper of a whisper of whisper, and the next thing I was going, oh, my gosh.
MCQUAY: The Navy had hydrophones spread across the north Atlantic and Pacific oceans. They'd been listening mostly for submarines. Other sounds were dismissed as just biologics.
CLARK: In my world, their noise was my data.
MCQUAY: The Navy let Clark record some of the sounds they were picking up. Then he built a device to shift the frequency so he could hear the deep sounds of whales better. And he heard voices he had never heard before, even thousands of miles away.
CLARK: I'm going, oh, I see. This is a telescope. Wow, I can do this over an ocean scale, not a little tiny bay. My life has never been the same.
MCQUAY: One thing Clark realized was that whales vocalize as they migrate. That meant that by listening, biologists could track those migrations, find out where they went, when and how far, something that was almost impossible to do by watching.
JOYCE: Chris was learning to think like a whale.
CLARK: I have dreams about being a blue whale. I simply want to bathe myself in that experience.
JOYCE: And he did. He kept hearing other sounds, noise, loud noise everywhere, the sound of ships' propellers.
CLARK: The noises that we're generating from our shipping traffic, from modern vessel, is clouding, is polluting the ocean. To me, it was like going to a restaurant where it's noisy, and you and I can barely have a conversation across the table.
JOYCE: Clark found that whales sometimes stop singing when they heard human-made sound and sometimes avoided the sources of that sound.
MCQUAY: Clark argued that ship sound was hazardous to whales. And in 2013, the International Maritime Organization set guidelines to make ships quieter, with new designs for propellers, for example.
JOYCE: A lot of people now study whale song, but it's still a mystery exactly why they do it. Clark says that's not surprising. They're not like us.
CLARK: I'm a blue whale. My heart beats once every minute, and my metronome is completely different than yours. And yet, I'm, as a human observer, am expecting their communication system to be somehow synchronized with mine. God forbid. You think we're supposed to understand what they're saying and doing just by listening to them in our mode? No.
MCQUAY: Whales, he says, have their own listening culture.
JOYCE: And they're not alone as we find out in our next story about the conversations of elephants in the African rain forest.
(SOUNDBITE OF ELEPHANTS)
JOYCE: I'm Christopher Joyce, NPR News.
MCQUAY: And I'm Bill McQuay.
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