Sound Waves

Sound waves are mechanical longitudinal waves that can be propagated in solids, liquids or gases. There is a very large range of frequencies over which such mechanical waves can be transmitted. The audible range is that range of frequencies which may be detected by the human ear. Mechanical waves in this range are called sound waves. The audible range is roughly between 20 Hz and 20 000 Hz. Waves with frequencies lower than the audible range are called infrasonic while those with frequencies above the audible range are called ultrasonic.