SOUND

What is Sound?

A sound is a vibration that propagates through a medium in the form of a mechanical wave. 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.

In physics, the sound is defined as

A vibration that propagates as an audible wave of pressure, through a medium such as a gas, liquid or solid. 

In psychology, the sound is defined as 

The reception of sound pressure waves and their perception by the brain.

What is a Soundwave?

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 energy wave propagation direction. When the atoms are set in vibration they move back and forth. This continuous back and forth motion results in a high-pressure and a low-pressure region in the medium. These high- pressure and low-pressure regions are termed compressions and rarefactions, respectively. These regions are transported to the surrounding medium resulting in the sound waves travelling from one medium to another.