Slew-induced distortion

Slew-induced distortion (SID or slew-rate induced distortion) is caused when an amplifier or transducer is required to change output (or displacement), i.e. slew rate, faster than it is able to do so without error.^[1] At such times any other signals may suffer considerable gain distortion, leading to intermodulation distortion.^[2] Transient intermodulation distortion may involve some degree of SID and/or distortion due to peak compression.

These are effects that tend to occur only during parts of a waveform fed through audio amplifiers, that may give rise to audible degradation of the sound quality in music, even when fixed-frequency harmonic distortion tests show low amounts of distortion for a simple sinewave test signal.^{[dubious – discuss][citation needed]}

TIM (Transient Intermodulation Distortion) was first discovered by Matti Otala in the 1960s due to accidentally wiring an amplifier incorrectly.^[3]