pure tone

A pure tone is a tone with a sinusoidal waveform, i.e. a sine or cosine wave. This means that regardless of other characteristic properties such as amplitude or phase, the wave consists of a single frequency. Sine and cosine waves are the most basic building blocks of more complex waves, and as additional frequencies (i.e. additional sine and cosine waves having different frequencies) are combined, the waveform transforms from a sinusoidal into a more complex shape.