How does the Human Ear Work? - The Human Body for Kids

Your ears are organs.
They aren’t just the flaps of skin you can see!
Your ears stretch deep into the skull.
They do a very important job.
They collect sound waves, which are tiny vibrations of air, and change them into signals that your brain can understand.
To do the difficult job of hearing, the ear has three different parts.
These are called the outer ear, the middle ear, and the inner ear.

What does the Outer Ear Do?

The outer ear consists of the ear flap, which is the part you can see, and a hollow tube, called the ear canal. This leads to the eardrum.
The eardrum is made of a sheet of skinlike material called a membrane.
This vibrates when sound waves travel down the ear canal.

What does the Middle Ear Do?

The middle ear is like a hollow cave.
It contains three bones, called the hammer, the anvil, and the stirrup. 
When the eardrum vibrates, it makes the hammer vibrate. This movement is passed on to the anvil and then to the stirrup.
The stirrup makes another membrane, called the oval window, vibrate.

What does the Inner Ear Do?

Behind the oval window is the inner ear. This is made up of the cochlea, the vestibule, and the semicircular canals. 
The cochlea has three tubes, which are coiled like a snail’s shell. These tubes are filled with fluid. When the oval window vibrates, it makes waves in the fluid.
One of the tubes has thousands of sensitive hairs.
When the fluid passes over the hairs, it prompts your nerves to carry messages about sound to your brain.

Vestibular System and Human Balance

The semicircular canals help you keep your balance.
They also contain fluid and sensitive hairs.
If you tip your head to one side, the fluid in these tubes moves, and the sensitive hairs let the brain know what has happened.
The vestibule is a chamber between the canals and the cochlea. 

It contains two sacs, also filled with fluid and sensitive hair cells.
The sacs have chalky particles inside them, which are pulled to the earth by the force of gravity. When you stand upright, the particles press on the hairs at the bottom of each sac.
When you lie down, the particles settle to one side and press on a different set of hairs.
Nerves from the hairs signal your brain about the position of your body.