Limiter

Limiters are common as a safety device in live sound and broadcast applications to prevent sudden volume peaks from occurring.

Treatments in order of decreasing severity range from clipping, in which a signal is passed through normally but sheared off when it would normally exceed a certain threshold; soft clipping which squashes peaks instead of shearing them; a hard limiter, 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 or a soft limiter which reduces maximum output through gain compression.

This is in contrast to standard hard limiting, as in an electric guitar fuzz box, where the harmonics are highly audible.

This device ultimately gives a distinctive character to the voice communication, which despite being highly distorted, ensures spoken words remain clear.

In AM radio, the information is located in the amplitude variations, and distortion can occur due to spurious signals that could cause the baseband to be misrepresented.

In Canada, while the cold weather rule is in effect, limiters are used to lower the capacity of houses of non-paying customers.