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Hi, everybody!

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I am a comparative anatomist.

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A comparative anatomist is someone[br]who studies the structure of the body

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of lots of different animals.

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And my favorite animals are whales.

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I like to study whales[br]because they're so interesting.

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They've adapted to a unique environment[br]of living in the water.

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And what I'm going to tell you[br]about is how whales make sounds

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by basically farting with their face.

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You know that they do this farting thing[br]with their blowhole;

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they blow out air like that,

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but they also use air[br]in lots of other ways.

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They use it for sound production,[br]which is what I'll focus on,

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but I also study other things[br]they do with air,

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like keep it out of their bloodstream[br]so they don't get bubbles,

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which is what happens[br]to human scuba divers

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when they get decompression sickness.

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But I'd like to start with the story

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of how these animals make[br]these farting noises,

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and that story begins with understanding[br]how hard it is to look at whales,

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because they live underwater[br]and they're really big,

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so they're hard animals to study.

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And in this picture --[br]you see that animal in the middle?

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That's a baby whale[br]and it's already the size of a bus!

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When you look at whales,[br]start with the top of their head

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because their nose[br]is on the top of their head,

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kind of like a built-in snorkel.

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They breathe through that[br]because they're mammals

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and mammals breathe air.

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Their nose can be opened and closed,

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as if you were to pinch it like this.

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You can see it's open in the bottom frame,[br]where the red arrows are.

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But not all whales have two nostrils.

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Whales include the groups[br]of dolphins and porpoises,

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and dolphins and porpoises,[br]the small whales,

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have only one nostril[br]on the top of their head,

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and they open and close that nostril

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by taking what is essentially[br]an upper lip, like this,

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and turning it back[br]over their nose, like this.

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That's how they open and close their nose.

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So when they make sounds,

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what they're basically[br]doing is a raspberry,

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(Makes raspberry sound)[br]which is kind of like a fart, right?

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Or up in New York,[br]we call it a Bronx cheer.

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And the way they do that

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is by taking that big,[br]fatty structure of a big fat lip,

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which, as you can see[br]here in this picture,

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which is a cut through the middle[br]of a dolphin's head,

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that big fat lip is that big[br]yellow portion there,

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and they roll it back and forth[br]over the top of their nose

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so that they vibrate it,

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kind of like when you let[br]the air out of a balloon

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and it makes that weird vibration sound.

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So this is what it sounds like[br]when they make their noise:

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(Vibration noise)

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Hear it? He'll do it again[br]when he faces the camera.

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(Vibration noise)

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Sounds like it's farting underwater.

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What that dolphin is actually doing,[br]though, is echolocation,

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which is making these series of pulses,

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and it uses it like a bat uses sonar.

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Well, a bat uses radar,[br]but when it's underwater it's sonar,

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so this animal is using sonar[br]to see its world in sound.

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Trying to understand how this works,[br]you have to look at it

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as if you were looking at the amplifier[br]speakers of a sound system.

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The small-toothed whales[br]are basically the "tweeters,"

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and the sound is coming[br]from that little nose

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that's moving back and forth[br]and coming out of their forehead.

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But the big whales[br]are kind of like the "woofers,"

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the big speakers that you have[br]in an amplifier system.

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And what's happening is their sound[br]is coming out of the throat.

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So if you tried to make[br]sound like a whale --

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make a sound right now, and go, "ahhhhhh."

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OK, now put your hand on your throat,[br]on your Adam's apple.

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You feel that vibration right there?

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That is lost energy for you,

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because that's not[br]how you communicate to everybody.

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You do it out of the mouth.

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But if you open your mouth underwater,[br]no one will hear you.

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You have to be able to take this energy[br]and amplify it through the water.

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That's what whales do.

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And when you hear their sound --

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(Squeaking sound)

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it's kind of like when you squeak[br]the air out of a balloon.

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So they get a lot of squeaky noises,

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but they also have this sound:

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(Vibrating sound)

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It sounds like it's farting, doesn't it?

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It's like it's got this giant[br]whoopee cushion in its throat.

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So, how do you know[br]that's what a whale is doing?

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Well, we study whales that come[br]to us from strandings.

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These are animals that die on the beach.

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Small whales like dolphins[br]and porpoises are easy;

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we can take them to the lab.

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But the big whales -- we've got[br]to bring the lab to the whale.

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And this is what that looks like.

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I'm the one in the middle[br]with the red hat.

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I'm not a very tall person,

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so you can see how big[br]this whale was compared to me.

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The whale is 65 feet long.

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And my scalpel is this little tool[br]on the side here.

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It basically looks like a hockey stick[br]with a blade on the end of it.

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And doing a dissection of a whale[br]is a very difficult process.

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You literally have to get into your work.

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It's kind of like a giant[br]bloody construction zone.

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You're wearing a hard hat,

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you're working with heavy machinery.

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In this case, by the way,

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that's just the voice box of a blue whale.

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Just the voice box.

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I'm only five feet tall --[br]you can see it's like 12 feet long.

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How do we know what's going on?

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Well, we look at the voice box, or larynx,

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and we see -- this is from a baby[br]whale so it's much smaller.

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You see this little u-shaped thing[br]I've outlined in blue.

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That's the part that's vibrating.

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It's kind of like our vocal folds.

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When I put my hand in there,[br]where that blue sleeve is,

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you can see there's a sack underneath it.

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That's the whoopee cushion.

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That's the air bubble or the balloon.

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So what these animals are doing --

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and you can see, there's this big[br]black balloon in the throat,

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where the digestive tract,[br]which is in blue,

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meets the breathing tract,[br]which is in light blue,

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and right in the middle[br]is that black sack.

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These animals are using[br]that sack to make these sounds.

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And so they vibrate that and send it out.

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Small-toothed whales also have air sacks;[br]they're all over their heads,

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so it's like they're airheads.

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They use this to capture[br]as much air as they can

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to take down with them[br]when they're diving,

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because when you dive, pressures increase,

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and that decreases the volume[br]of air you have available.

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But more importantly,

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having that sack allows them[br]to recycle the air that they're using,

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because air is a precious commodity.

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You don't want to have to go[br]back up to the surface to get more.

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So when you make a sound underwater,[br]if you're a whale --

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let's hear you start making[br]a sound, go "ahhhh."

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But whales keep their mouths[br]closed, so go "ahhhmm."

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(Audience makes noise)

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You're all humming, right?

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But whales keep their nose[br]closed and go, "mmmm."

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(Makes noise)

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What happened?

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You can't make the sound anymore[br]once you close your nose

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because you've pressurized the system.

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Whales, by having air sacks, keep[br]themselves from pressurizing the system,

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which means the air continues to flow,

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and so if you had a bag[br]on the end of your nose,

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you'd be able to make[br]air continue to flow.

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So I hope you've enjoyed that.

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That's what a comparative anatomist[br]does for a living.

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We study the structure of these animals.

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We try to mimic it; we apply it[br]back to the human situation,

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maybe making new technologies[br]for protective devices

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or maybe even making[br]new treatments for medicines

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for people's diseases who mimic[br]these weird environments.

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So I hope you enjoyed that. Thank you.

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(Applause)