Single-frequency sound waves are sinusoidal waves. Although pure single-frequency sound waves do not occur naturally, they can be created artificially by means of a computer. ... If we're talking about a pure sine wave, then the wave's amplitude, A, is the highest y value of the wave.

Why are sound waves sinusoidal?

The air molecules themselves do not move very far, but wave of high density air moves at the speed of sound, roughly 770 miles per hour. To represent such cyclic behavior mathematically, think of the air pressure at a listener's location as a function of time described by a sine wave or sinusoid.

Is every sound a sine wave?

All sounds in nature are fundamentally constructed of sine waves. More complex sounds simply contain more oscillations at different frequencies, stacked one upon another. Higher-frequency, oscillations which are tonally related to the fundamental frequency (the base note or tone) are known as harmonics.