# What is the inner ear?

An episode of [Science for Kids / Science's Not Boring: The Kids Science Podcast](https://invisiblenetwork.ai/podcast/1896928296), 8 Sep 2026, 12 min.

Audio: https://www.buzzsprout.com/2624612/episodes/19734932-what-is-the-inner-ear.mp3

Have you ever spun around super fast on a tire swing, stopped, and felt like the whole room was still twirling? Join Mira and Finn as they shrink down and travel deep into the weird, wet world inside your skull to find out why! You won't believe it, but you actually have tiny tubes of secret fluid and thousands of microscopic crystals hiding inside your ears! These amazing 'ear rocks' and sloshing liquids act like a 3D navigation computer to keep you balanced and tell your brain which way is up. Find out what happens when that fluid gets confused, how lightning-fast electrical signals shoot to your brain at 250 miles per hour, and why spinning ice skaters don't fall over on the ice! Plus, discover what happens to brave astronauts when they float in zero gravity and their ear crystals stop working completely! Put your balance to the test, learn some mind-blowing human biology, and find out exactly why we get dizzy. It is going to be a totally spin-tastic adventure!

## Transcript

[0:00] SPEAKER_00: Welcome to Science Is Not Boring by kidopoly.com.
[0:03] SPEAKER_00: I'm Mira.
[0:04] SPEAKER_00: And I'm Finn.
[0:05] SPEAKER_00: We have some amazing listeners to shout out today.
[0:08] SPEAKER_00: A huge hello to five-year-old Emma in San Diego, California.
[0:12] SPEAKER_00: She loves hearing where all the other kids are listening from.
[0:16] SPEAKER_00: That's right.
[0:16] SPEAKER_00: And our episode today is specially for seven-year-old Daphne in the UK.
[0:21] SPEAKER_00: Daphne loves arts, crafts, and getting dizzy.
[0:24] SPEAKER_00: And she asked us exactly why spinning makes us feel so wobbly.
[0:29] SPEAKER_00: This one is for you, Daphne.
[0:30] SPEAKER_00: It is such a great question.
[0:33] SPEAKER_00: Because have you ever spun around on a tyre swing or an office chair 50 times in a row, stopped, and felt like the whole room was still twirling around you?
[0:43] SPEAKER_00: Oh, absolutely.
[0:45] SPEAKER_00: One time I spun around the backyard, tried to walk in a straight line, and just fell right over into the grass.
[0:52] SPEAKER_00: The ground felt like it was totally tilted.
[0:55] SPEAKER_00: Well, what if I told you the reason you fall over is because you have microscopic crystals and tiny tubes of secret fluid hidden deep inside your skull.
[1:05] SPEAKER_00: Wait, what?
[1:06] SPEAKER_00: Crystals inside my head?
[1:09] SPEAKER_00: Are those actually supposed to be in there?
[1:12] SPEAKER_00: They absolutely are.
[1:14] SPEAKER_00: Today we are exploring the wild, wet, and slightly weird world of human balance.
[1:19] SPEAKER_00: Okay, Mira, explain these head crystals to me.
[1:22] SPEAKER_00: Where exactly are they hiding?
[1:24] SPEAKER_00: First, let's take a journey deep into your ear.
[1:28] SPEAKER_00: We have to go past the outer ear you can see, past the eardrum, and into a hidden bony cave called the inner ear labyrinth.
[1:36] SPEAKER_00: Labyrinth?
[1:37] SPEAKER_00: It sounds like a secret underground maze.
[1:40] SPEAKER_00: It actually looks like one.
[1:42] SPEAKER_00: Right next to the snail-shaped part that hears sounds, there is a tiny, weirdly shaped organ.
[1:48] SPEAKER_00: The whole thing is only about the size of a single green pea, and it's called the vestibular system.
[1:54] SPEAKER_00: The vestibular system?
[1:57] SPEAKER_00: That sounds like a fancy navigation computer on a rocket ship.
[2:01] SPEAKER_00: It acts exactly like a rocket's navigation computer.
[2:05] SPEAKER_00: The main part has three tiny curved tubes called the semicircular canals.
[2:11] SPEAKER_00: Each loop they form is about 6.5 millimeters across, roughly the size of a pencil eraser.
[2:18] SPEAKER_00: Three little loops?
[2:19] SPEAKER_00: Why do we need exactly three?
[2:21] SPEAKER_00: Because we move in three-dimensional space.
[2:24] SPEAKER_00: One loop tracks when you nod, yes, up and down.
[2:28] SPEAKER_00: Another tracks when you shake your head, no, side to side.
[2:32] SPEAKER_00: Oh I get it.
[2:33] SPEAKER_00: And what does the third one do?
[2:35] SPEAKER_00: The third loop tracks when you tilt your head left to right, like bringing your ear all the way down to touch your shoulder.
[2:42] SPEAKER_00: Whoa! So it's a complete 3D tracking system built right into our skulls.
[2:48] SPEAKER_00: But what's inside these tubes?
[2:50] SPEAKER_00: Are they filled with air?
[2:51] SPEAKER_00: Nope.
[2:52] SPEAKER_00: They are filled with a special watery fluid called enderlymph.
[2:56] SPEAKER_00: It has a thickness very close to regular water.
[2:59] SPEAKER_00: Ew, watery earliquid.
[3:02] SPEAKER_00: That is so weird and kind of gross.
[3:04] SPEAKER_00: It gets weirder.
[3:06] SPEAKER_00: Floating in that fluid at the end of each loop is a tiny clump of jelly called the cupula.
[3:12] SPEAKER_00: Oh, oh man, jelly too?
[3:14] SPEAKER_00: My head is like a weird science kitchen experiment.
[3:17] SPEAKER_00: It really is.
[3:19] SPEAKER_00: Now, trapped inside that jelly are thousands of microscopic hairs called stereocilia.
[3:25] SPEAKER_00: Wait, hair inside the jelly?
[3:28] SPEAKER_00: Inside the watery fluid?
[3:30] SPEAKER_00: Inside the pea-sized loops?
[3:32] SPEAKER_00: How does that even help us balance?
[3:34] SPEAKER_00: Picture holding a clear glass of water.
[3:37] SPEAKER_00: If you suddenly spin the glass on a table, the water inside doesn't move right away, right?
[3:43] SPEAKER_00: Yeah, it sort of sloshes back and takes a second to catch up with the glass.
[3:47] SPEAKER_00: That's a rule of physics called inertia.
[3:50] SPEAKER_00: The exact same thing happens in your head.
[3:52] SPEAKER_00: When you spin around, your head moves, but the enderlymph fluid lags behind.
[3:57] SPEAKER_00: Oh, so the fluid is sloshing around inside the tiny loops?
[4:02] SPEAKER_00: Yes, and as that liquid washes through the loops, it pushes on those comps of jelly.
[4:07] SPEAKER_00: And what happens to the thousands of tiny hairs trapped in the jelly?
[4:11] SPEAKER_00: They bend, and when those hairs bend, they act like tiny electrical switches.
[4:16] SPEAKER_00: They fire off signals straight to your brain, travelling along your nerves at speeds up to 250 miles per hour.
[4:24] SPEAKER_00: Whoa, 250 miles per hour?
[4:27] SPEAKER_00: That's faster than a race car.
[4:29] SPEAKER_00: Right! That lightning far signal tells your brain, hey, we are spinning to the left.
[4:35] SPEAKER_00: In fact, a scientist named Robert Barani won a Nobel Prize in 1914 just for figuring out how this amazing fluid works.
[4:44] SPEAKER_00: Okay, that is genius.
[4:45] SPEAKER_00: But Daphne wanted to know why we get dizzy.
[4:48] SPEAKER_00: If the fluid just tells us we're spinning, why do we fall over when we finally stop?
[4:54] SPEAKER_00: Ah, that's where the inertia comes back to trick us.
[4:57] SPEAKER_00: When you suddenly stop spinning, your head stops moving immediately.
[5:01] SPEAKER_00: But does the watery fluid stop?
[5:04] SPEAKER_00: No! The fluid keeps swirling around inside the tubes for a few more seconds, just like water still spinning in a cup after you set it down.
[5:13] SPEAKER_00: Wait, so the liquid keeps pushing the jelly and bending the hairs, even when I'm standing perfectly still.
[5:19] SPEAKER_00: Exactly! Your inner ear is screaming to your brain.
[5:23] SPEAKER_00: We are still spinning at top speed, but your eyes are looking at the room, telling your brain, no, we aren't, we completely stopped.
[5:30] SPEAKER_00: So the brain is getting two totally different messages at the exact same time.
[5:35] SPEAKER_00: That sounds chaotic.
[5:37] SPEAKER_00: It is! Your brain gets completely confused by the mixed signals.
[5:42] SPEAKER_00: That confusion is what makes the room feel like it's whirling, and it's what we call dizziness.
[5:48] SPEAKER_00: Haha, that makes so much sense.
[5:51] SPEAKER_00: But wait, earlier you promised me crystals in my head.
[5:56] SPEAKER_00: I haven't heard about any crystals yet.
[5:58] SPEAKER_00: Right.
[5:59] SPEAKER_00: Below the three loops are two tiny sacs called the utricle and the saccule.
[6:04] SPEAKER_00: And sitting on top of a flat layer of jelly in those sacs are thousands of microscopic calcium crystals.
[6:12] SPEAKER_00: The crystals! What are they actually called?
[6:16] SPEAKER_00: Scientists call them otoconia, which is Greek for eardust.
[6:20] SPEAKER_00: Because they are heavier than the jelly, Earth's gravity always pulls them straight down.
[6:26] SPEAKER_00: Oh, so when I took my head forward to tie my shoes, the heavy eardust slides forward.
[6:32] SPEAKER_00: You got it! They pull on more tiny hairs, and that tells your brain which way is down.
[6:37] SPEAKER_00: It's how you can tell you're upside down even if you're in a pitch black room.
[6:42] SPEAKER_00: That is incredible design.
[6:44] SPEAKER_00: But wait, what if there is no gravity to pull them down?
[6:48] SPEAKER_00: Like for astronauts floating in space?
[6:51] SPEAKER_00: Such a brilliant question! When astronauts blast into orbit, they are in microgravity.
[6:57] SPEAKER_00: Without gravity holding them down, those tiny ear crystals just float around randomly.
[7:03] SPEAKER_00: Oh no! So the brain suddenly has no idea which way is up or down?
[7:08] SPEAKER_00: Nope.
[7:09] SPEAKER_00: It causes a condition called space adaptation syndrome, or space sickness.
[7:14] SPEAKER_00: Nearly 80% of astronauts get it during their first few days.
[7:19] SPEAKER_00: Ew, do they throw up in zero gravity?
[7:22] SPEAKER_00: That sounds incredibly messy.
[7:24] SPEAKER_00: It definitely can be.
[7:26] SPEAKER_00: In 1985, an astronaut named Jake Garn got so terribly space sick that NASA jokingly invented the Garn scale, where one Garn is the maximum level of dizziness.
[7:39] SPEAKER_00: Wow.
[7:40] SPEAKER_00: But how do they ever get any work done up there?
[7:43] SPEAKER_00: Well, after about three days, the astronaut's brain does something amazing.
[7:48] SPEAKER_00: It figures out the ear crystals are useless in space, so it hits the meat button and ignores them entirely.
[7:55] SPEAKER_00: The brain just ignores a whole organ.
[7:57] SPEAKER_00: That is so cool.
[7:59] SPEAKER_00: But what happens when they land back on Earth?
[8:01] SPEAKER_00: Gravity turns the ear crystals back on, and their brains have to relearn how to balance all over again.
[8:08] SPEAKER_00: Sometimes they even have trouble walking for a few days.
[8:11] SPEAKER_00: That is wild! The fact that microscopic ear dust controls everything we do is blowing my mind.
[8:18] SPEAKER_00: It gets even cooler when you look at professional athletes.
[8:22] SPEAKER_00: Think about Olympic ice skaters.
[8:24] SPEAKER_00: They can spin up to 300 times per minute.
[8:27] SPEAKER_00: That's five full rotations every single second.
[8:31] SPEAKER_00: Five spins a second?
[8:33] SPEAKER_00: Their ear fluid must be an absolute tornado.
[8:36] SPEAKER_00: Why don't they just fall over onto the ice?
[8:39] SPEAKER_00: You might guess they use a trick called spotting.
[8:42] SPEAKER_00: Ballet dancers keep their eyes locked on one single spot on the wall, then whip their head around super fast, but ice skaters spin too fast.
[8:51] SPEAKER_00: Oh, so they don't snap their head around in quick steps like ballet dancers do.
[8:56] SPEAKER_00: Exactly.
[8:57] SPEAKER_00: But more amazingly, scientists scanned the brains of professional skaters and found their brains actually change over time.
[9:05] SPEAKER_00: They literally learn to block out the dizzy signals from the inner ear.
[9:09] SPEAKER_00: No way.
[9:10] SPEAKER_00: They train their brains to be totally dizzy-proof.
[9:13] SPEAKER_00: Yes.
[9:14] SPEAKER_00: And speaking of keeping vision steady, did you know pigeons bob their heads when they walk to stabilise their sight?
[9:21] SPEAKER_00: They lock their head in place while their body steps forward, keeping their vision perfectly still, but not to prevent dizziness.
[9:29] SPEAKER_00: I am never going to look at pigeons walking or my own ears the same way again.
[9:34] SPEAKER_00: Alright, Finn, it's time for the balance quiz.
[9:37] SPEAKER_00: Let's see if you are paying attention to all those microscopic details.
[9:42] SPEAKER_00: Okay, my inner ear is steady and my brain is ready.
[9:45] SPEAKER_00: Let's do this.
[9:47] SPEAKER_00: First question.
[9:48] SPEAKER_00: What are the three tiny loops in our inner ear called?
[9:56] SPEAKER_00: Next one.
[9:57] SPEAKER_00: What is the special watery fluid inside those loops called?
[10:05] SPEAKER_00: Question three.
[10:06] SPEAKER_00: What invisible force pulls down on our tiny ear crystals?
[10:14] SPEAKER_00: Here's number four.
[10:16] SPEAKER_00: How many days does it take an astronaut's brain to adapt and ignore the floating crystals in space?
[10:26] SPEAKER_00: Last question.
[10:28] SPEAKER_00: What visual trick do ballet dancers use to keep from getting dizzy?
[10:36] SPEAKER_00: Great job! Let's see how you did.
[10:39] SPEAKER_00: The first answer is they are called the semicircular canals.
[10:44] SPEAKER_00: For question two, the liquid is called endolymph.
[10:48] SPEAKER_00: Number three, the answer is gravity pulls the crystals down.
[10:54] SPEAKER_00: Question four, it takes about three days for astronauts to adapt.
[10:59] SPEAKER_00: And the final answer is they use a technique called spotting.
[11:04] SPEAKER_00: Wow! I actually remembered most of those.
[11:07] SPEAKER_00: I honestly still can't believe we have actual crystals rolling around inside our heads.
[11:14] SPEAKER_00: I know.
[11:15] SPEAKER_00: Human biology is just so weird and wonderful.
[11:18] SPEAKER_00: And the next time you get dizzy, Daphne, you'll know exactly what that sloshing ear fluid is doing in there.
[11:25] SPEAKER_00: Hey everyone, if you were amazed by the hidden rocks in your ears today, please give us a five-star review.
[11:31] SPEAKER_00: Just scroll down on your podcast app and tap the five stars.
[11:35] SPEAKER_00: Yes, please do.
[11:37] SPEAKER_00: Oh, and don't forget to head over to our site, kidopoly.com.
[11:41] SPEAKER_00: We've got tons of fun learning games and activities waiting for you there.
[11:45] SPEAKER_00: And if you want to shout out on the show, or just want to tell us your favourite weird science fact, send us an email at hello at kidopoly.com.
[11:54] SPEAKER_00: Thanks for exploring with us.
[11:56] SPEAKER_00: See you next time on Science Is Not Boring.
[12:01] SPEAKER_00: Keep your balance.

Shows are listed from Apple Podcasts' charts and directory, and Podcast Index where it is used. Every show and episode belongs to its publisher and plays from the publisher's own feed; this site hosts none of them.