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Echoes and sonar - CCEASound waves

Sound is caused by the vibration of particles but not all vibrations can be heard as sound. Common ideas about sound come from the limited range of vibrations that human ears can detect.

Part of Physics (Single Science)Waves

Sound waves

Sound waves are waves.

They cause particles to vibrate parallel to the direction of wave travel.

The vibrations can travel through solids, liquids or gases.

The speed of sound depends on the medium through which it is travelling.

When travelling through air, the speed of sound is about 340 m/s.

Sound cannot travel through a because there are no particles to carry the vibrations.

The ear

A diagram of the human ear

The human ear detects sound.

Sound waves enter the and cause the eardrum to vibrate.

Three small bones transmit these vibrations to the .

This produces electrical signals which pass through the to the brain, where they are interpreted as sound.