Sound waves need a material or a medium to propagate therefore, they are called mechanical waves. They rely on the particles in the medium to transport their energy.
Waves that require a medium such as solid, liquid or gas to travel are known as mechanical waves. A sound wave is the pattern of disturbance caused by the energy travelling away from the source of the sound.
- Sound waves are longitudinal waves. This means that the propagation of vibration of particles is parallel to the direction of the energy wave propagation.
- The medium in which it propagates can either be a solid, a liquid or a gas. Sound travels fastest in solids, relatively slower in liquids and slowest in gases.
- Hence sound is a vibration that propagates through a medium in the form of a mechanical wave.