WEBVTT

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Hi, everybody!

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I am a comparative anatomist.

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A comparative anatomist is someone
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
because they're so interesting.

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

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And what I'm going to tell you
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
with their blowhole;

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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,
which is what I'll focus on,

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but I also study other things
they do with air,

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

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which is what happens
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
these farting noises,

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and that story begins with understanding
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 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,
start with the top of their head

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because their nose
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
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,
where the red arrows are.

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But not all whales have two nostrils.

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Whales include the groups
of dolphins and porpoises,

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and 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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(Makes raspberry sound)
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

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

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which, as you can see
here in this picture,

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which is a cut through the middle
of a dolphin's 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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(Vibration noise)

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Hear it? He'll do it again
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,
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,
but when it's underwater it's sonar,

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

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

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as if you were looking 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 nose

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

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But the big whales
are kind of like the "woofers,"

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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
is coming out of the throat.

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So if you tried to make
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,
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
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,
no one will 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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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
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
whoopee cushion in its throat.

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So, how do you know
that's what a whale is 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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Small whales like dolphins
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
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
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 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
on the side here.

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It basically looks like a hockey stick
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.

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Just the voice box.

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I'm only five feet tall --
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
whale so it's much smaller.

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You see this little u-shaped thing
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,
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
black balloon in the throat,

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where the digestive tract,
which is in blue,

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meets the breathing tract,
which is in light 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;
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
as much air as they can

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to take 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,

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having that sack allows them
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
back up to the surface to get more.

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

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

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But whales keep their mouths
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
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
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
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 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
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 people's diseases who mimic
these weird environments.

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So I hope you enjoyed that. Thank you.

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(Applause)