Mechanical Longitudinal Waves

Sound is a vibration that spreads across a medium (i.e., air or water) as a mechanical longitudinal wave formed by pressure. A Mechanical longitudinal wave can also be called compression wave as it generates compressions and rarefaction when traveling through a medium. (Sound Is a Pressure Wave - Physics Classroom)

The amplitude of a sound wave is the difference between the pressure of the undisturbed air and the maximum pressure caused by the wave. The Speed of sound deviates with the temperature, and density of the medium that it goes through. The speed of sound is generally expressed as 343 meters per second at a temperature of 20 oC. In 1709, William Derham, Rector of Upminster, discovered the speed of sound was at 1,072 parisian feet per second. By using a telescope from a tower Derham observed the flash of a distant shotgun being fired, and then measured the time until
During propagation, waves can be reflected, refracted, or attenuated by the medium. With this in mind a sound wave can change its direction through space, meaning its displacement can be altered through time by a force exerted over it. Sound waves moving through air can generally be distorted by two factors. One is a complex relationship between the density and pressure of the medium. This relationship, affected by temperature, determines the speed of sound within the medium. The other is the Motion of the medium itself. If the medium is moving, this movement may increase or decrease the absolute speed of the sound wave depending on the direction of the movement. For example, sound moving through wind will have its speed of propagation increased by the speed of the wind if the sound and wind are moving in the same direction. If the sound and wind are moving in opposite directions, the speed of the sound wave will be decreased by the speed of the wind (Rugh, Wilson