OneTaskBy Tim King · Updated
Noise Gate Online
Gate Audio Below a Threshold to Remove Background Noise Between Words
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How the Noise Gate works
This noise gate online needs no plugin or upload. A noise gate opens when the sound is loud enough and closes when it is not. Between words the hiss, hum and room tone drop away; during words nothing changes. Set the threshold just above the background level, adjust how fast the gate opens and closes, and preview. The file stays in your browser.
How the noise gate online works
Constant background noise — a fan, a fridge, traffic, hiss from a cheap microphone — is most noticeable in the gaps. While someone is speaking it is masked; the moment they pause it is all you hear. A gate removes it from the gaps. It does not remove noise that overlaps the speech, which is a job for spectral noise reduction, but on a typical voice recording the gaps are where the noise is annoying.
Threshold. The level below which the gate closes, in decibels below full scale. Look at the waveform, find the quietest spoken passage and the loudest silence, and set the threshold between them. Speech usually sits above -30 dBFS and room noise below -45, so the default of -40 is a fair start. Too high and the gate chops off soft syllables and word endings; too low and it never closes.
Attack. How fast the gate opens once the signal crosses the threshold. A few milliseconds is right for speech; slower attacks soften the start of each word audibly. Very fast attacks on percussive material can click, so ease to 1 or 2 ms if that happens.
Hold. How long the gate stays open after the signal falls below the threshold before it starts to close. This is the control that stops chattering — the rapid open-close flutter between syllables and on sustained notes with tremolo. A hundred milliseconds bridges the gaps inside a word; raise it if word endings are clipped.
Release. How long the gate takes to close once the hold has elapsed. A fast release sounds abrupt, exposing the moment the noise vanishes; 100 to 300 ms lets it fade naturally. For music with long decays use much longer releases so reverb tails are not cut.
Reduce instead of mute. A gate that closes to total silence can sound unnatural — the room disappears and returns with each phrase. Setting Reduce by to 12 or 20 dB leaves a bed of quiet room tone that keeps the recording feeling continuous while taking the noise well down. Broadcast engineers call this a downward expander and it is usually the better choice for speech.
Stereo. The gate is controlled by the louder of the channels and applies the same gain to both, so the image does not shift when it opens.
FAQ
The gate is cutting off the ends of words. What do I change?
Lower the threshold a few decibels, lengthen the hold to 200 ms and lengthen the release. Quiet consonants at word endings fall below the threshold before the word is really over, and hold is what bridges that gap.
Why does the noise seem to pulse on and off?
Because a full mute makes the contrast between gate open and gate closed obvious. Use Reduce by around 15 dB rather than muting completely, so the room tone is lowered rather than removed, and lengthen the release so the transition is a fade instead of a switch.
Will it remove noise during speech?
No. A gate only acts when the whole signal is below the threshold, and during speech it is above. Noise that sits under the voice needs spectral noise reduction, which this page does not do. The gate is for the gaps, and combined with a high-pass filter it handles most rumble and hiss.
How is it different from the silence remover?
The silence remover cuts the quiet sections out, making the file shorter. The gate keeps the timing exactly as it is and simply turns the quiet sections down. Use the gate for speech that must stay in sync with video or with other tracks.
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