# Parts of the Human Ear

By Z M

Topic: Human Body & Medicine

[Open the interactive Jig](https://ask.jig.com/j/AazTLPS1EIks)

## Guide

### 1. Meet your ear

This is a model of a human ear, much bigger than life, set into a slice of the side of the head\. The part you can see is only the beginning: most of your ear is hidden inside your skull\. Drag anywhere to turn the model\.

The tiny inner parts are made extra big in this model so you can see them\.

### 2. The outer ear

The curly flap is the auricle, also called the pinna\. It is a sheet of bendy cartilage covered in skin, and its folds catch sound and funnel it into the ear canal\. The soft earlobe at the bottom has no cartilage at all\.

The shape of your pinna also helps you tell whether a sound comes from in front or behind\.

### 3. A look inside

Let's slice the model open\. Your ear has three parts: the outer ear catches sound, the middle ear is a tiny air space with three bones, and the inner ear, deep in the bone, turns sound into signals for your brain\.

### 4. The eardrum

The ear canal is a tunnel about 2\.5 centimeters long\. At its end sits the eardrum, a thin, tight skin about as wide as a pea\. Sound waves make it shake\. Slide the loudness and watch it move\.

Ear wax keeps the canal clean and slowly moves out on its own\.

### 5. Three tiny bones

Behind the eardrum, three bones pass the shaking along: the hammer, the anvil and the stirrup\. The stirrup is the smallest bone in your body, only about 3 millimeters tall\. Together they make the push about 20 times stronger\.

The real movement is far too small to see\. Here it is shown much bigger and slower\.

### 6. The cochlea hears pitch

The stirrup pushes on the oval window of the cochlea, a snail\-shaped tube full of fluid\. Tiny hair cells inside turn the ripples into nerve signals\. High notes are picked up near the start of the spiral, low notes near its tip\.

Unrolled, the cochlea would be about 3 centimeters long\. It coils about two and three\-quarter turns\.

### 7. Keeping your balance

Your inner ear has a second job: balance\. Three looped semicircular canals sit at right angles to each other\. When you turn your head, the fluid inside them swirls, and the vestibule next to them senses which way is down\.

### 8. Why ears pop

The Eustachian tube links the middle ear to the back of your throat\. When you swallow or yawn, it opens for a moment and lets air in or out\. That evens out the air pressure on both sides of the eardrum, and you feel a pop\.

### 9. Sound's whole journey

Follow a sound: the pinna catches it, the eardrum shakes, the three bones pass it on, and the cochlea turns it into signals\. The hearing nerve carries them to your brain, which tells you what you hear\.

Young people can hear pitches from about 20 to 20,000 vibrations each second\.