> ## Content Index
> Fetch the complete content index at: https://ffmpeguru.com/llms.txt
> Use this file to discover other available public pages before exploring further.

# Gate quiet audio below a threshold
- URL: https://ffmpeguru.com/gate-quiet-audio-below-a-threshold/
- Published: 2026-09-08T09:00:00.000Z
- Updated: 2026-10-13T17:59:43.000Z
- Author: FFmpeguru
- Tags: ffmpeg

![](https://picsum.photos/seed/ffback27/1200/630)

A noise gate is the audio equivalent of a mute button that engages when the level drops below a threshold. It silences background noise between spoken phrases, removes room tone from a quiet section, and cleans up the gaps in a music track. The \`agate\` filter in libavfilter is a one-line gate with attack, hold, and release controls.

## The command

```
ffmpeg -i in.wav -af "agate=threshold=-50dB:ratio=9:attack=20:release=1000" out.wav
```

## What it does

The filter watches the audio level, and when it falls below the threshold, it reduces the gain by the ratio. A threshold of -50 dB with a ratio of 9:1 means a signal at -60 dB (10 dB below the threshold) is reduced to -110 dB (effectively silence). The attack and release control how fast the gate engages and disengages, in milliseconds. The output is a file with the quiet sections muted.

## Requirements

Any audio input. The filter is in libavfilter. CPU-only, single-pass. The default values are reasonable for spoken voice; for music, raise the attack to 50 ms to preserve the natural decay of each note.

## Things to avoid

- Setting the threshold too high. A threshold of -20 dB will cut the quiet consonants of speech (t, s, f), making the voice sound chopped.
- Using a very fast release. The gate will engage and disengage rapidly, producing a 'pumping' artifact. Raise the release to 200-500 ms for a smoother transition.
- Gating a music track with a soft dynamic range. The gate will cut the reverb tail and the room tone, making the music sound unnatural.
- Replacing a noise gate with a compressor. A compressor smooths the level; a gate mutes the level. They are different tools for different jobs.