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Hi everybody. I am a comparative anatomist,

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and a comparative anatomist is someone who studies

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the structure of the body of lots of different animals.

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And my favorite animals are whales,

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and I like to study whales because they are so interesting.

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They've adapted to a unique environment

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of living in the water.

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And what I'm going to tell you about is

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how whales make sounds by

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basically farting with their face.

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Now, you know that they do this farting thing

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with their blowhole; they blow out air like that,

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but they also use air in lots of other ways.

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They use it for sound production,

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which is what I'm going to focus on,

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but I also study other things they do with air,

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like how they keep it out of their blood streams

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so that they don't get bubbles,

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which is what happens to human scuba divers

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when they dive and they get decompression sickness.

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But what I'd like to do is start with the story

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of how these animals make these farting noises,

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and that story begins with understanding

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how hard it is to look at whales

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because they live underwater and they're really big,

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so they're hard animals to study.

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And just in this picture, you see that animal in the middle?

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That's a baby whale and it's already the size of a bus.

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When you look at whales, you have to start

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with the top of their head, because their nose

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is on the top of their head.

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It's kind of like a built-in snorkel.

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And they breathe through that because they're mammals

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and mammals breathe air.

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And their nose can actually be opened and closed,

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kind of as if you were to pinch it like this,

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so you can see, it's open in the bottom frame there

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where the red arrows are.

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But not all whales have two nostrils.

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Whales includes the groups of dolphins and porpoises,

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and the dolphins and porpoises, the small whales,

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have only one nostril 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 an upper lip, like this,

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and turning it back 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 doing is a raspberry,

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like [mouth noises], which is kind of like a fart, right?

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Or up in New York we call it a Bronx cheer.

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And the way they do that is by taking

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that big fatty structure of a big fat lip,

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which is, as you can see here in this picture,

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which is a cut through the middle of a dolphins head,

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that big fat lip is that big yellow portion there,

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and they roll it back and forth 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 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 when they make their noise:

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[dolphin noise]

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You hear that? It's going to do it again

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when he faces the camera.

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[dolphin noise]

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Sounds like its farting underwater.

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What that dolphin is actually doing though

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is echolocation, 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, but when it's underwater

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it's sonar, so this animal is using sonar

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to see its world in sound.

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Trying to understand how this works,

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you have to look at it as if you were looking

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at the amplifier speakers of a sound system.

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The small toothed whales are basically the "tweeters,"

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and the sound is coming from that little

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nose that's moving back and forth

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and coming out of their forehead.

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But when you look at the big whales,

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they're kind of link the "woofer,"

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the big speakers that you have in an amplifier system.

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

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So if you tried to make sound like a whale,

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you just make a sound right now,

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like go "ah."

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Okay, now put your hand on your throat,

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on your Adam's apple, you feel that vibration right there?

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That is lost energy for you

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because that's not how you're communicating to everybody.

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You're doing it out of the mouth.

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But if you open your mouth underwater,

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no one is going to hear you.

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You have to be able to take this energy and amplify it through the water,

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and that's what whales do.

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And when you hear their sound,

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[whale sounds]

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Hear that? It's kind of like when you squeak 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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[whale noises]

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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 whoopie cushion in its throat.

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So, how do you know that's what a whale's doing?

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

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These are animals that die on the beach.

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Now the small whales, like dolphins and porpoises are easy,

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we can take them back to the lab.

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But the big whales, we've got to bring the lab to the whale.

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And this is what that would look like.

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So I'm the one in the middle 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 this whale is compared to me.

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The whale is 65 feet long, and my scalpel

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is this little tool on the side here.

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It basically looks like a hockey stick

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with a blade on the end of it.

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And doing a dissection of a whale 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 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; just the voice box.

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And I'm only five feet tall, so you can see,

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it's already like twelve feet long there.

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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 inside.

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This is from a baby whale so it's much smaller.

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You see this little "u" shaped thing

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that I've outlined in blue;

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that's the part that's vibrating.

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That's kind of like our vocal folds.

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And when I put my hand in there,

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that's 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 whoopie 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 in this picture,

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there's this big black balloon in the throat,

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where the digestive track, which is in blue,

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meets the breathing track, which is in light blue,

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so you have light blue and dark blue,

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and right in the middle is that black sack.

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These animals are using 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,

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and they're all over their heads,

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so it's kind of like they're airheads.

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And they use this to capture as much air as they can,

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to take it down with them when they're diving,

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because when you dive, pressures increase,

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and that decreases the volume of air you have available.

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But more importantly, having that sack allows them to

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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 back up to the surface

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to get more air.

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So when you make a sound underwater,

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if you're a whale,

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let's here you start making a sound.

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Go "ah."

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But whales keep their mouths closed, so go

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[mouth noises]

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You're all humming, right?

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But whales keep their nose closed, so go

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[mouth noises]

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What happened? You can't make the sound anymore

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once you close your nose because you've pressurized the system.

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So whales by having air sacks

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keep 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 on the end of your nose,

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you'd be able to make 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 does for their living.

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We study the structure of these animals.

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We try to mimic it.

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We apply it back to the human situation,

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maybe making new technologies for protective devices,

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or maybe even making new treatments for medicines

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for peoples' diseases who mimic these weird environments.

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So I hope you enjoyed that. Thank you.