with Chloe and the Nurb.

[MUSIC PLAYING]

[MUSIC PLAYING]

(SINGING) A-skiddly bob, a-booma lotta chakka boom boom, yeah!

Woo.

Tell me where it hurts.

I'm singing, not hurting.

(SINGING) A-doo diddly dee!

Um, I do love the drums.

I am drumming in honor of today's quest-- (SINGING)

To the ear to see how we hear.

So you're playing the drum because we're

going to learn how the drum in your ear helps you hear.

That was the plan, but having managed to climb up this tree--

You found that the getting down part is not so easy?

Precisely.

No worries, as the ear is coming here to hear.

Delightful!

Before we enter, did you know that there

are three parts to the ear?

Three parts?

Sing it, Nurb.

(SINGING) The outer ear, the middle ear, and the inner ear.

Woo hoo hoo.

I'm guessing that this, being on the outside,

would be the outer ear?

What a clever Chloe you are.

The outer ear, also known as the pinna or auricle--

(SINGING) Fancy word!

The pinna, or outer ear, acts like a funnel,

collecting sounds to channel them into the ear canal, which

is also part of the outer ear.

What are we waiting for?

Let's head inside the outer ear.

Ew, what's this gunk on the floor?

You mean this glorious earwax produced by the ear canal?

Nasty earwax is more like it.

Hardly.

Earwax contains chemicals to fight off

infections that could hurt the skin here

in the ear canal and traps dirt to help keep it clean.

OK, fighting infection and keeping the ear canal clean

is important stuff.

Uh, yeah.

Also, earwax will help us slide down the ear canal!

Woo hoo hoo!

To the middle ear!

Where we find the eardrum!

[LOUD DRUMMING]

Quietly, my dear Chloe.

The eardrum is a very sensitive instrument.

[SOFT DRUMMING]

Ah, much better.

Like my bongo drum, the eardrum is a thin piece

of tightly-stretched skin.

Do they work the same?

Very much the same.

And also different.

Such a Nurb thing to say.

Explain.

A musical drum makes sound when we hit it,

but no one's hitting the drum in your ear.

The sound waves that your outer ear collected

cause it to vibrate.

Sound waves vibrate the eardrum?

Got it.

What happens next?

When the eardrum vibrates, it moves

a set of three tiny bones on the other side called ossicles.

Ossicles?

That sounds like a drum beat.

(CHANTING) Ossicles, ossicles, ossicles.

The three ossicle bones are called the hammer, the anvil,

and the stirrup.

Huh.

Those bones sort of look like those things.

But the sound's journey to the brain isn't over yet, is it?

Not even close.

For that, we need to pop past the ear drum to the inner ear.

There are the ossicles.

And there's the cochlea.

(SINGING) The ossicle bones connected to the cochlea.

The cochlea is a small, circled tube filled with liquid.

The vibration of the ossicles create waves

in the liquid in the cochlea.

Are those little hairs I see?

I'm so happy you asked.

The cochlea is lined with tiny hairs.

When the fluid in the cochlea moves, it moves the hairs

and creates nerve signals that get sent to the brain.

The brain understands these nerve signals as sound,

and so you hear.

What?

I said, you hear!

Sorry, I can't hear you.

That's because you have earplugs in your ears!

A precaution in case you started singing again.

Oh ho!

What a fine idea.

(SINGING) Three parts to the ear you

will need if you want to hear-- outer, middle, and inner ear!

Scoop doop doo boo.

Sound gets funneled in the pinna through an ear canal

to the middle ear, where the sound makes the eardrum

vibrate, moving the--

(CHANTING) Ossicles, ossicles, ossicles, ossicles.

(SINGING) Ossicles move the liquid

in the cochlea in the inner ear, which

moves the tiny hairs inside the cochlea,

sending nerve signals to your brain so you can hear!

Skiddly doop, doop doop, doop doop, I hear you.

[MUSIC PLAYING]