Sound is a vibration that propagates as an acoustic wave through a medium such as a gas (air), liquid (water), or solid. It is created by a vibrating object, which causes the particles in the surrounding medium to vibrate and transmit the wave. These vibrations travel as longitudinal waves, where the particles move parallel to the direction of wave propagation, creating alternating regions of compression (high pressure) and rarefaction (low pressure) in the medium

. Sound does not exist in a vacuum because it requires a medium to travel through. When these sound waves reach our ears, they cause the eardrum to vibrate, and these vibrations are interpreted by the brain as sound

. The frequency of these waves determines the pitch we hear, while the amplitude affects loudness. In summary, sound is a mechanical wave resulting from vibrations that travel through an elastic medium and are perceived by our auditory system as auditory sensations