Distortion

This term refers to changes of a sound waveform which occur in electroacoustic systems. It can also refer to certain non-linear effects in the inner ear.

See: Aural Harmonics, Combination Tones, Diplacusis, Recruitment. Compare: Fidelity.

Problems in an electroacoustical system which produce distortion are the following:

• the inability to maintain linearity, resulting in the addition of unwanted harmonics, called Harmonic Distortion (see peak clipping), or other tones, called Intermodulation Distortion (see combination tones);
• the inability to pass the complete audio spectrum equally, called Frequency Distortion (see also 'foldover' under sound synthesis);
• the inability to handle transients, called Transient Distortion (see transient response);
• the inability to pass all signals in the same amount of time, called Phase Distortion. Compare: Phasing.

In electronic music and some kinds of modern popular music, distortion is exploited for musical purposes. The composer may alter the waveform of the original sound by various modulation techniques. The rock group often creates distorted effects by means of feedback or by overloading the amplifiers and speakers.

See also: Flutter, Limiter, Mixing, Modulation, Oscilloscope, VU Meter, Wow.