Glossary
Noise gate
An audio processor that mutes or lowers a track when its level drops below a set threshold.
A noise gate is an audio processing tool, either hardware or software, that automatically lowers or completely mutes a channel whenever its signal drops below a set threshold. When someone stops talking, the gate closes and cuts the low-level hiss, room tone or hum that would otherwise still be audible during silence.
This is useful for cleaning up a multi-mic recording where each host's channel picks up a little bleed from the other person's mic, since gating a mic closed when its owner is not speaking reduces that bleed and tightens up the overall mix. It is applied during editing rather than while recording, working from the already captured track.
A gate set too aggressively can clip off the start of quiet words or leave odd artifacts when someone trails off mid-sentence, so threshold and release time need to be tuned by ear rather than left at a default. Noise gating works best as a cleanup step after gain staging and room treatment, not as a replacement for either, since it hides a noisy room rather than fixing it.