Okay, just one more photo.
Say cheese.
Nice.
Oh, hi there.
Squeaks is going on a trip around the world and because I can't go with him, he's bringing Tiny Jesse to keep him company.
But since Tiny Jesse doesn't have real eyes like I do, he's going to take photos with this camera so I can see all of the cool stuff that he experienced.
Oh, I hadn't thought of that.
Squeaks is wondering how I might be able to hear all of the cool places he's going to visit.
You are going to hear lots of amazing sounds on your trip, like rushing waterfalls or chirping birds or people playing musical instruments.
And just like Tiny Jessie can't see like I can, she also can't hear.
Those tiny ears of hers sure are cute, but They aren't real.
So let's think about how ears work and then use that to find a way that you can help me hear the sounds of your adventure after you get back.
Sounds can help us understand if there's a friend talking to us or popcorn popping or a thunderstorm rumbling.
Our ears are body parts that can help our brains hear and understand sounds.
And once we understand a sound, we can make a decision like go get some of that yummy popcorn or hurry inside before it starts to rain.
That's right!
It's super helpful!
Now, each sound is a special kind of wave that can move through the air or water or even solids like wood.
And it does that by wiggling tiny particles in the air or this table just a little bit.
Can you see the wave moving through it?
When a sound wave reaches my ear, it first runs into the auricle.
That's the big flappy part of the ear that helps collect sound waves and directs them into the auditory canal.
But you have other ear parts that are inside your head, so we're not done yet.
All that wiggling air travels down the auditory canal and starts to wiggle a special part of your ear that looks a bit like the head of a drum.
Exactly, the eardrum.
Although scientists have another name for it too, the tympanic membrane.
No, the eardrum doesn't wiggle my brain.
In fact, everything from the auricle to the eardrum is considered to be part of the outer ear.
But behind the eardrum, there's also the middle ear and the inner ear.
Yeah, there really is a lot more to the ear than you might think.
The middle ear is where the sound waves get amplified, or made stronger.
And in this particular spot you've got three teeny tiny bones that move.
That stronger signal to the inner ear.
The inner ear is the home to the structure called the cochlea.
It's shaped kind of like a snail shell.
And inside of it, there's some liquid and a bunch of teeny tiny hairs.
Uh, no, not like the hairs on my head.
They're really a kind of nerve, which is a cell that can send messages to other parts of your body.
So when the bones from the middle ear bring the sound wave to the cochlea, the hairs start to wiggle too, which finally sends a signal to your brain.
And then your brain can take all that information and go, hey, I heard something.
Ooh, good question!
Squeaks wants to know if I can hear all kinds of vibrations.
I can't hear every kind of sound wave.
If a sound wave is too quiet, it won't get all the parts in my ear wiggling.
But also, it has to be the right pitch.
You can think about pitch as the different notes.
You can play on a keyboard or sing using your voice.
Here's an example of a higher pitch.
And here's an example of a lower pitch.
And depending on my pitch, I can wiggle the air a little bit differently.
But just like musical instruments can only make a certain range of pitches, human ears can only hear sound waves within a certain range of pitches.
If the pitch is too low or too high, We can't hear it no matter how loud it is.
But that's not all because, just like every human can't see the exact same colors, we don't all hear the same sounds.
For example, many people lose the ability to hear certain pitches as they get older or if different parts of their ears get damaged.
Also, some people are born unable to hear some or all of the sounds that others can.
People who are deaf or hard of hearing might use technology to help them hear, like a hearing aid to make sounds louder, or a device called a cochlear implant that sends vibrations straight to the nerves and skips over the rest of the ear.
That isn't working so well.
Yeah, there are lots of people who use tools like these, of all ages, too.
Everyone's ears are different.
But that's not just true for humans.
It's also true for other animal species.
Lots of animals can hear sounds that humans normally can't, or can't hear sounds that humans normally can.
Say, let's call someone who I know has some pretty impressive ears.
Hi, Sam.
Oh, hi, Bill.
Hi, Jessie.
Hi, Squeaks.
I'm helping Bill with a project.
I'm making Webb a red hat for his birthday.
He's going to love it whether he wants to or not.
What are you two up to?
Well, Squeaks and I, we're talking about how ears work.
And I know that you have some... Some pretty amazing ears.
Man, I love my ears.
Bats like me tend to have really big auricles to funnel sound waves into our ears, but most of us also have really big cochlea for how small our bodies are.
And we have extra nerves to help us hear really quiet sounds and really high pitches.
That's right, Squeak's way higher than Jesse can hear.
It's super helpful because a lot of bats use echolocation to get around.
We make a very high-pitched noise with our mouth and after the sound wave travels for a bit, it might hit something like a tree or a bug and bounce back to us.
When our ears pick up this bounced back sound wave, we know there's a tree that we don't want to accidentally fly into or there's a tasty bug to eat.
That's super useful, Sam.
And Bill, I was curious about something.
I know that you don't have auricles like Sam and I do, but do you mind if I ask how birds hear?
No problem.
Even though we don't have those flappy bits sticking out of our heads, birds still have an auditory canal and eardrum, a middle ear that makes sound waves stronger and an inner ear with nerves that send information to the brain about those sound waves.
Our ear parts look a little different, but they work a lot like yours.
Whoa, that's so cool.
Thanks.
We've got to finish up here, but we'll come visit soon.
Bye.
Bye!
Wow, different animals have some incredible ways of understanding sound with their ears, and I think I have an idea.
This camera can take pictures, but it can also record video, and more importantly, audio.
You can use it to help you record all of the awesome sound waves you come across on your trip.
And Tiny Jessie might not have real ears, but this will help you to save sounds for me to experience later.
Take a moment to listen to all of the sounds that are happening around you right now.
If it's too quiet, make some of your own.
Low pitches, high pitches, everything in between.
But if you want to be loud, maybe check to see if it's okay with anyone else in the room first.
And if you want to keep learning with Squeaks and me and all of our friends, make sure to join us next time here at the Fort.
