High Quality Content by WIKIPEDIA articles! A Noise Gate or gate is an electronic device or software that is used to control the volume of an audio signal. In its most simple form, a noise gate allows a signal to pass through only when it is above a set threshold: the gate is `open`. If the signal falls below the threshold no signal is allowed to pass (or the signal is substantially attenuated): the gate is `closed`. A noise gate is used when the level of the `signal` is above the level of the `noise`. The threshold is set above the level of the `noise` and so when there is no `signal` the gate is closed. A noise gate does not remove noise from the signal. When the gate is open both the signal and the noise will pass through.