Sound Waves

Sound Waves

1. Sound waves are longitudinal waves.

   • Properties of Waves
     • The frequency of a sound wave is related to the pitch that is heard: high frequency sound waves are high pitched low frequency sound waves are low pitched The amplitude of a sound wave is related to the volume of the sound: high amplitude sound waves are loud low amplitude sound waves are quiet. Oscilloscope traces showing the following sounds: quiet, low pitch sound loud, low pitch sound loud, high pitch sound

2. They cause particles to vibrate parallel to the direction of wave travel. The vibrations can travel through solids, liquids or gases.

3. The speed of sound depends on the medium through which it is travelling. When travelling through air, the speed of sound is about 330 metres per second (m/s). Sound cannot travel through a vacuum because there are no particles to carry the vibrations.

4. The ear The human ear detects sound. Sound waves enter the ear canal and cause the eardrum to vibrate. Three small bones transmit these vibrations to the cochlea. This produces electrical signals which pass through the auditory nerve to the brain, where they are interpreted as sound.