Sound is produced from a vibrating object. It has different characteristic parameters like amplitude, frequency, time period, etc. Amplitude of vibration is defined as the maximum displacement of the vibrating object on either side of its equilibrium position. The SI unit of amplitude is metre.

When an object is vibrating, the energy is transferred to the adjacent medium particles. The medium particles transfer the energy from one to another. In this way, the energy of a wave propagates through a medium. A vibrating object produces sound, which needs a medium to propagate. Sound is a mechanical energy that propagates through a medium by the process of condensation and rarefaction. Any wave propagating through a medium is known as matter waves. The speed of sound wave depends on the density of the medium.