A distortion is the alteration of the original shape (or other characteristic) of an object, image, sound, waveform or other form of information or representation. Distortion is usually unwanted. In some fields, distortion is desirable, such as
electric guitar (where distortion is often induced purposely with the
amplifier to achieve the electric guitar's desired, electrifying, aggressive sound). The slight distortion of analog
tapes and
vacuum tubes is considered pleasing in certain situations. The addition of
noise or other extraneous signals (
hum,
interference) is not considered to be distortion, though the effects of distortion are sometimes considered noise.
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