A noise gate is an automatic mute button. When the sound reaching your microphone is quieter than a level you choose, the gate closes and your viewers hear nothing. When you speak, the level jumps above that line, the gate opens, and your voice goes through. That is the whole idea. Everything else in the settings panel exists to make the opening and closing smooth enough that nobody notices it happening.
What a gate can and cannot do
Picture a doorman with one rule: loud enough gets in, too quiet stays out. He does not inspect what the sound is. A gate has no idea whether it is hearing your voice, a keyboard, or a dog. It only measures level.
Two consequences follow from that. First, a gate is excellent at cleaning up the gaps between sentences. The fan hum, the faint game audio leaking from your headphones, the chair squeak while you wait in a lobby all vanish, because during those moments nothing is loud enough to open the door. Second, a gate does nothing about noise while you are talking. Once your voice opens it, the fan hum walks in right alongside you. Removing noise underneath speech is a job for noise suppression, which is a different filter. Most streamers end up running both, with suppression placed above the gate.
The five controls, in plain language
OBS includes a noise gate among its built-in audio filters, and it exposes five sliders. They look intimidating, but each one answers a simple question.
The two thresholds
The open threshold answers: how loud must a sound be before the gate lets it through? The close threshold answers: how quiet must things get before the gate shuts again? There are two separate lines, rather than one, so that the gate does not chatter. If a single line did both jobs, a voice hovering right at that level would flick the gate open and shut many times a second, which sounds like a bad phone connection. Keeping the close threshold a little below the open threshold gives the gate a zone in which it holds its current state.
Attack, hold and release
Attack is how quickly the gate opens once the open threshold is crossed. Keep it fast, or the first consonant of every sentence gets shaved off. Hold is how long the gate stays open after the level drops, which covers the tiny pauses inside natural speech. Release is how gradually it fades shut. A slightly longer release sounds more natural than an abrupt cut, because the tail of your last word fades instead of being chopped.
Finding your numbers
There is no universal correct setting, because every room and microphone is different, but the method is the same for everyone. Sit silently and watch the mic meter in the OBS mixer to see where your room noise sits. Then talk at your quietest realistic volume, the mumbling late-night-stream voice, and see where that lands. Your thresholds belong in the space between those two readings: close threshold a bit above the room noise, open threshold a bit below your quietest speech.
If that space is tiny, the gate will struggle no matter what you do, and the fix lies elsewhere. Move the mic closer to your mouth, lower the input gain, or add noise suppression ahead of the gate so the background drops further. For a slider-by-slider version of this process, a guide to setting up an OBS noise gate is worth keeping open in another tab while you experiment.
Mistakes nearly everyone makes at first
The most common one is setting the thresholds too high. It feels safe, because the keyboard disappears completely, but the cost is clipped word beginnings and whole quiet phrases going missing. Viewers find a voice that cuts in and out far more annoying than a faint hum.
The next is judging the result while live. You cannot hear your own gate properly while talking. Record thirty seconds locally instead, including silence, soft speech, laughter and typing, then listen back on headphones. Pay attention to the starts and ends of sentences.
The last is expecting the gate to solve keyboard noise. If you type while you talk, the gate is already open and every keystroke passes. Mic placement and suppression handle that problem, and the gate just mops up afterwards.
What to take away from all this
A gate is a simple tool with a narrow job: silence when you are silent. Set the two thresholds between your room noise and your quietest voice, keep the attack fast, give the release some room, and test with a recording instead of your ears in the moment. Done well, nobody will ever know it is there, and that is exactly how you know it is working.
