Noise Suppression vs Noise Gate — Which Is Better for Mic Audio?

If you've looked into reducing background noise from your microphone, you've encountered both "noise gate" and "noise suppression" as options in OBS, DAWs, and streaming tools. They're both called noise reduction but they work completely differently — and choosing the wrong one produces obvious audio artifacts.

Here's how each works, when to use each, and why most microphone applications are better served by noise suppression than a noise gate.

How a Noise Gate Works

A noise gate monitors the input signal's volume level. When the signal drops below a defined threshold, the gate closes — cutting the audio to silence (or near silence). When the signal rises above the threshold, the gate opens and passes audio through.

Settings you typically configure on a noise gate:

• Threshold: The volume level below which audio is cut. Set above your background noise level, below your voice level.
• Attack: How quickly the gate opens when the signal exceeds the threshold. Too slow clips the start of words.
• Release: How long the gate stays open after the signal drops below threshold. Too short creates choppy cuts; too long lets noise through after you stop speaking.
• Hold: Minimum time the gate stays open once triggered.

The problem: a noise gate applies the same threshold to everything — background noise AND quiet speech. If you lower your voice, start a sentence quietly, or trail off at the end of a phrase, the gate may close and cut that audio. It doesn't distinguish between "quiet noise" and "quiet voice."

How Noise Suppression Works

Noise suppression analyzes the frequency content of the audio signal — not just its volume. It identifies which frequencies are consistently present (your background noise) and which frequencies appear intermittently and with speech-like patterns (your voice).

Two common approaches:

• Spectral subtraction: Sample the noise profile during a quiet moment, then subtract those specific frequencies from the ongoing signal. This is what the browser denoiser uses — it's fast, computationally light, and very effective on steady noise (fans, HVAC).
• AI/ML-based suppression: A trained neural network distinguishes human speech from non-speech in real time. This is what Krisp and NVIDIA Broadcast use — it handles complex and intermittent noise (keyboard typing, conversations in background) better than spectral subtraction.

Neither approach uses a volume threshold. Noise suppression can reduce background noise while your voice is quiet, and it doesn't create hard cuts between words the way a gate can.

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When to Use a Noise Gate vs. Noise Suppression

Use noise suppression when:

• Your background noise is consistent (fan, HVAC, hum) and you want it removed during speech AND during pauses
• You want natural-sounding silence between sentences rather than abrupt cuts to total silence
• You want a "set it and forget it" approach — suppression adapts to your noise profile without manual threshold tuning

Use a noise gate when:

• You have very loud, intermittent noise that you only need to mute during complete silence (drums in an adjacent room, very loud HVAC that cuts in and out)
• You are recording in a multi-mic setup where channel bleed between instruments is the primary concern — a classic studio use case
• You want to prevent low-level ambient noise from appearing in quiet sections of a recording

Best approach for most microphone users: Noise suppression as the primary tool, noise gate as an optional secondary tool for handling extreme silence-time bleed. Running both in sequence (suppression first, then gate) is common in OBS and DAW filter chains.

Noise Gate vs. Noise Suppression in OBS Studio

OBS Studio offers both in its Audio Filters panel. Common configurations:

Noise Suppression only: Add the Noise Suppression filter to your microphone. Use RNNoise for AI-based suppression or Speex for lighter CPU usage. Good for most streaming setups with steady background noise.

Noise Gate only: Add a Noise Gate filter. Set the close threshold above your background noise floor and the open threshold below your quiet speech level. Works for preventing dead-air noise but can clip quiet speech.

Combined (recommended for noisy environments): Add Noise Suppression first, then Noise Gate second. Suppression reduces continuous noise; gate handles any remaining bleed during complete silences. Set the gate threshold lower than you would without suppression, since suppression has already reduced the noise floor.

Filter order in OBS matters — audio passes through filters top to bottom in the filter list. Put Noise Suppression before Noise Gate.

Frequently Asked Questions

Which produces better results for streaming — noise gate or noise suppression?

For streaming, noise suppression (especially RNNoise in OBS or a dedicated tool like the browser denoiser) produces more natural-sounding audio. A noise gate creates abrupt silence cuts that are audible to viewers. Noise suppression maintains a more natural ambient character while removing the identifiable noise.

Does the browser mic denoiser use a noise gate or noise suppression?

It uses a spectral noise gate — a form of noise suppression that works by sampling your specific room noise and subtracting those frequencies from the signal. It operates on frequency content, not just volume level, which is why it performs better than a simple threshold-based gate for steady background noise.

Can I run noise suppression and a noise gate at the same time in OBS?

Yes, and it's a common practice. Put Noise Suppression first in the filter list (it runs first) and Noise Gate second. The suppression reduces continuous noise, and the gate handles any remaining ambient noise during complete silence periods.

Why does my noise gate make my audio sound choppy?

This usually means the attack or release settings are too fast, causing the gate to open and close rapidly. Increase the release time so the gate stays open longer after you stop speaking. Also check that your open threshold is set low enough to capture quiet speech without re-triggering the close-open cycle.