Hi, everybody!

I am a comparative anatomist.

A comparative anatomist is someone
who studies the structure of the body

of lots of different animals.

And my favorite animals are whales.

I like to study whales
because they're 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.

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'll focus on,

but I also study other things
they do with air,

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

which is what happens
to human scuba divers

when they get decompression sickness.

But I'd like to 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 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,
start with the top of their head

because their nose
is on the top of their head,

kind of like a built-in snorkel.

They breathe through that
because they're mammals

and mammals breathe air.

Their nose can be opened and closed,

as if you were to pinch it like this.

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

But not all whales have two nostrils.

Whales include the groups
of dolphins and porpoises,

and 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,

(Makes raspberry sound)
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, as you can see
here in this picture,

which is a cut through the middle
of a dolphin's 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:

(Vibration noise)

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

(Vibration noise)

Sounds like it's 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 the big whales
are kind of like the "woofers,"

the big speakers that you have
in an amplifier system.

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

So if you tried to make
sound like a whale --

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

OK, 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 communicate to everybody.

You do it out of the mouth.

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

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

That's what whales do.

And when you hear their sound --

(Squeaking sound)

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:

(Vibrating sound)

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

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

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

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

These are animals that die on the beach.

Small whales like dolphins
and porpoises are easy;

we can take them to the lab.

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

And this is what that looks like.

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 was 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.

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

How do we know what's going on?

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

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

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

That's the part that's vibrating.

It's kind of like our vocal folds.

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

you can see there's a sack underneath it.

That's the whoopee cushion.

That's the air bubble or the balloon.

So what these animals are doing --

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

where the digestive tract,
which is in blue,

meets the breathing tract,
which is in light 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;
they're all over their heads,

so it's like they're airheads.

They use this to capture
as much air as they can

to take 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.

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

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

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

(Audience makes noise)

You're all humming, right?

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

(Makes noise)

What happened?

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

because you've pressurized the system.

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 a 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 people's diseases who mimic
these weird environments.

So I hope you enjoyed that. Thank you.

(Applause)