and a comparative anatomist is someone who studies

the structure of the body of lots of different animals.

And my favorite animals are whales,

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

They've adapted to a unique environment

of living in the water.

And what I'm going to tell you about is

how whales make sounds by

basically farting with their face.

Now, you know that they do this farting thing

with their blowhole; they blow out air like that,

but they also use air in lots of other ways.

They use it for sound production,

which is what I'm going to focus on,

but I also study other things they do with air,

like how they keep it out of their blood streams

so that they don't get bubbles,

which is what happens to human scuba divers

when they dive and they get decompression sickness.

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

of how these animals make these farting noises,

and that story begins with understanding

how hard it is to look at whales

because they live underwater and they're really big,

so they're hard animals to study.

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

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

When you look at whales, you have to start

with the top of their head, because their nose

is on the top of their head.

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

And they breathe through that because they're mammals

and mammals breathe air.

And their nose can actually be opened and closed,

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

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

where the red arrows are.

But not all whales have two nostrils.

Whales includes the groups of dolphins and porpoises,

and the dolphins and porpoises, the small whales,

have only one nostril on the top of their head,

and they open and close that nostril

by taking what is essentially an upper lip, like this,

and turning it back over their nose, like this.

That's how they open and close their nose.

So when they make sounds,

what they're basically doing is a raspberry,

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

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

And the way they do that is by taking

that big fatty structure of a big fat lip,

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

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

that big fat lip is that big yellow portion there,

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

so that they vibrate it,

kind of like when you let the air out of a balloon

and it makes that weird vibration sound.

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

[dolphin noise]

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

when he faces the camera.

[dolphin noise]

Sounds like its farting underwater.

What that dolphin is actually doing though

is echolocation, which is making these series of pulses,

and it uses it like a bat uses sonar.

Well a bat uses radar, but when it's underwater

it's sonar, so this animal is using sonar

to see its world in sound.

Trying to understand how this works,

you have to look at it as if you were looking

at the amplifier speakers of a sound system.

The small toothed whales are basically the "tweeters,"

and the sound is coming from that little

nose that's moving back and forth

and coming out of their forehead.

But when you look at the big whales,

they're kind of link the "woofer,"

the big speakers that you have in an amplifier system.

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

So if you tried to make sound like a whale,

you just make a sound right now,

like go "ah."

Okay, now put your hand on your throat,

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

That is lost energy for you

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

You're doing it out of the mouth.

But if you open your mouth underwater,

no one is going to hear you.

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

and that's what whales do.

And when you hear their sound,

[whale sounds]

Hear that? It's kind of like when you squeak the air out of a balloon.

So they get a lot of squeaky noises,

but they also have this sound:

[whale noises]

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

It's like it's got this giant whoopie cushion in its throat.

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

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

These are animals that die on the beach.

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

we can take them back to the lab.

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

And this is what that would look like.

So I'm the one in the middle with the red hat.

I'm not a very tall person,

so you can see how big this whale is compared to me.

The whale is 65 feet long, and my scalpel

is this little tool on the side here.

It basically looks like a hockey stick

with a blade on the end of it.

And doing a dissection of a whale is a very difficult process.

You literally have to get into your work.

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

You're wearing a hard hat,

you're working with heavy machinery.

In this case, by the way,

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

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

it's already like twelve feet long there.

How do we know what's going on?

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

and we see inside.

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

You see this little "u" shaped thing

that I've outlined in blue;

that's the part that's vibrating.

That's kind of like our vocal folds.

And when I put my hand in there,

that's where that blue sleeve is,

you can see there's a sack underneath it.

That's the whoopie cushion.

That's the air bubble or the balloon.

So what these animals are doing,

and you can see in this picture,

there's this big black balloon in the throat,

where the digestive track, which is in blue,

meets the breathing track, which is in light blue,

so you have light blue and dark blue,

and right in the middle is that black sack.

These animals are using that sack to make these sounds.

And so they vibrate that and send it out.

Small toothed whales also have air sacks,

and they're all over their heads,

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

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

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

because when you dive, pressures increase,

and that decreases the volume of air you have available.

But more importantly, having that sack allows them to

recycle the air that they're using

because air is a precious commodity.

You don't want to have to go back up to the surface

to get more air.

So when you make a sound underwater,

if you're a whale,

let's here you start making a sound.

Go "ah."

But whales keep their mouths closed, so go

[mouth noises]

You're all humming, right?

But whales keep their nose closed, so go

[mouth noises]

What happened? You can't make the sound anymore

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

So whales by having air sacks

keep themselves from pressurizing the system

which means the air continues to flow,

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

you'd be able to make air continue to flow.

So I hope you've enjoyed that.

That's what a comparative anatomist does for their living.

We study the structure of these animals.

We try to mimic it.

We apply it back to the human situation,

maybe making new technologies for protective devices,

or maybe even making new treatments for medicines

for peoples' diseases who mimic these weird environments.

So I hope you enjoyed that. Thank you.