Two different tools both promise to keep noise out of your calls. A noise gate decides when your mic is open. Noise suppression decides what passes while it is. Most chat apps give you some of each, often under other names.
The gate: a threshold
A gate compares your mic’s level with a threshold. Above it, everything passes; below it, the gate closes and the call hears silence. RØDE sums it up: a noise gate reduces or mutes signals below a set threshold, so only sounds above it, typically your voice, get through.
In chat apps the gate usually goes by another name:
| App | What it is called | How it decides |
|---|---|---|
| Discord | Voice Activity, with Input Sensitivity | Your level against a marker, set automatically or by you |
| Steam voice chat | Voice transmission threshold | Your level against a threshold you can raise to High or turn off |
| TeamSpeak | Voice activation | Detects speech; Auto Settings sets it from a few sentences |
A gate’s strength is silence in your pauses. Its weaknesses follow from the threshold:
- Noise gets through while you talk. When the gate is open for your voice, it is open for the fan behind you too.
- Loud noises open it. A keypress can cross the threshold like a word. Valve’s advice, when friends hear typing, is to raise the threshold.
- Quiet speech can’t open it. Set the threshold too high and soft words vanish. Valve says that if people hear parts of your words cut off, lower the threshold or turn it off.
The first word cut off
The most common gate complaint is a clipped start: “ello” instead of “hello”. A soft first syllable sits below the threshold, so the gate opens a moment too late. Discord’s advice is to set the marker between your softest speaking voice and any other noise, low enough that it doesn’t cut you off when you speak softly. It also warns that automatic sensitivity can cut off the ends of sentences when your volume swings, and that Voice Activity carries an inherent 200 ms delay.
Two fixes beat fiddling with the slider. Move the mic closer, so even soft words stand well clear of the room. Or use push to talk, which opens the mic when you press a key: Discord says it has relatively no delay when you press, and its release delay keeps the end of your sentence.
Suppression: removing noise as you speak
Suppression works on the sound itself, all the time. Classic filters learn what steady noise sounds like and take it out. Audacity’s Noise Reduction learns from a stretch of noise on its own, and its manual says the method suits constant sounds such as hiss, hum and fan noise, but not irregular noise such as traffic.
The filters in chat apps use machine learning to go further. Discord says Krisp removes background noises that aren’t human voices, such as barking dogs, vacuums and slamming doors, while still sending your voice. Google names typing, a closing door and building work for Meet.
Because suppression keeps working while you talk, it can take the fan out from under your voice, which a gate can’t. Its failures are different:
- It can take some of your voice. Discord says Krisp can lower voice quality in a quiet room with a good mic, and Audacity warns that a more sensitive setting may remove some of the sound you want to keep.
- It can leave artifacts. Audacity describes them as random bursts of very short tones, sometimes called musical noise, left behind when the noise was underestimated.
- It usually keeps other voices. Krisp and Meet’s noise cancellation leave human voices in. Separate modes target them: Voice isolation in Teams, Optimize for my voice in Webex, and Zoom’s High level.
- It needs processing power. Zoom notes that its High level may use more CPU, and Discord turns Krisp off when your CPU is very busy.
Which to use
| Noise gate | Noise suppression | Push to talk | |
|---|---|---|---|
| Your pauses | Silent | Noise turned down | Silent unless you hold the key |
| Noise while you talk | Passes through | Removed or reduced | Passes through |
| Soft words | Cut if below the threshold | Can be thinned at strong settings | Kept |
| Keyboard clicks | Open the gate if loud enough | Many apps name typing | Only while you hold the key |
For most calls, start with the app’s suppression at its default level and leave the gate on automatic, or off. Add push to talk if you type a lot or share a room. A gate on its own works best in a quiet, steady room, set by watching your softest words, not your loudest.
The noise test shows the two numbers a threshold has to fit between: your noise floor in the first step and your speech level in the second. If the gap between them is under 20 dB, the test’s own line for usable, no threshold will separate them cleanly. Fix the distance first.