Hearing and the structure of the ear

In a nutshell

Sounds are made by vibrations of an object. This makes the air around it vibrate which forms sound waves. Sound waves enter your ears and you hear them as sounds.

Sounds

When an object vibrates it shakes back and forth very quickly. This vibrates the air around it, which forms sound waves that travels through the air to your ear.

You cannot always see the vibrations and sound waves causing sounds. Sometimes they are so small that the human eye can't see them.

Tip: Remember, when you hear a sound it means something is vibrating!

Example

When you speak, your vocal cords vibrate. This makes the surrounding air also vibrate. These vibrations form sound waves and travel to your ears. You can hear this as speech.

The ear

The ear is a fragile part of the body designed to pick up sound waves.

Sound waves enter the ear and reach the ear drum. The ear drum starts vibrating as well. The ear drum sends these vibrations to the brain and you hear them as sounds.

Science; Sound; KS2 Year 4; Hearing and the structure of the ear

1.	Ear canal	A tube which carries the sound waves from the outer ear to the inner ear. It contains ear wax which helps keep out infections and traps dirt.
2.	Eardrum	A thin piece of skin which vibrates when sound waves hit it.
3.	Ear bones	Made up of the anvil, the hammer and the stirrup. These are small bones that carry vibrations.
4.	Cochlea	Vibrations are converted to a signal (message) that the brain can understand.
5.	Auditory nerve	Sends the signal to the brain.