Limiting: Any process by which a specified characteristic (typically amplitude) of the output of a device is prevented from exceeding a predetermined value.

Limiting can refer to non-linear clipping, in which a signal is passed through normally but "sheared off" when it would normally exceed a certain threshold. It can also refer to a type of variable-gain audio level compression, in which the gain of an amplifier is changed very quickly to prevent the signal from going over a certain amplitude.

Hard limiting ("clipping") is a limiting action in which there is

(a) over the permitted dynamic range, negligible variation in the expected characteristic of the output signal, and

(b) a steady-state signal, at the maximum permitted level, for the duration of each period when the output would otherwise be required to exceed the permitted dynamic range in order to correspond to the transfer function of the device.

Soft limiting is limiting in which the transfer function of a device is a function of its instantaneous or integrated output level. The output waveform is therefore distorted, but not clipped.

This article contains material from the Federal Standard 1037C (in support of MIL-STD-188), which, as a work of the United States Government, is in the public domain.