distortion

2.44  distortion. (a) Any change in the shape of a waveform not resulting from linear addition of another waveform. (b) Undesired change of waveform.

Annotation 1          Multiplication by a constant and time delay do not constitute distortion. Noise and certain desired changes in waveform, such as those resulting from modulation or detection, are not usually described as distortion.

Annotation 2          Harmonic distortion is harmonic power divided by fundamental power or the square root of this ratio. Use of power or the square root of the ratio should be clarified for the description of harmonic distortion.