What Is A Noise Gate? (And When To Use It)

A noise gate is an effective tool that you can use to help clean up your recording, podcast, or live stream. In this guide, we’ll show you how it works, when to use it, when to avoid it, and give you some tips and tricks along the way.

Quick Answer: You can think of a noise gate as a way to automatically mute your microphone when you’re not using it. If your signal (volume) drops below a predetermined level, the noise gate will mute your audio signal (typically a microphone). A noise gate is commonly used to prevent drum mics from bleeding into each other and for live streamers to reduce background noise on their live stream.

How Does A Noise Gate Work?

A noise gate works by setting a threshold (gate) for the incoming audio, and if the audio signal falls below this threshold, the gate will close and mute the audio. This can be useful for removing unwanted background noise or hum from a recording.

To use a noise gate effectively, you must adjust the threshold level to match the background noise level in your recording. This can be done by listening to the recording and adjusting the threshold until the background noise is reduced to an acceptable level. It is important to set the threshold carefully, as setting it too high can result in the gate cutting off the beginning or end of words, making the audio sound unnatural.

Commonly, you will have several other variables that you can use to control your noise gate as well:

Attack: The attack time of a noise gate is the amount of time it takes for the gate to open after the input signal reaches the threshold level. This will control how quickly the noise gate responds to changes in the input signal. For example, if a noise gate is used to reduce mic bleed on a drumset, a short attack time can help prevent the gate from opening too slowly and missing the first contact of a drumstick on a drum.

Hold: The hold time of a noise gate is the amount of time that the gate stays open after the input signal drops below the threshold. This is useful for preventing the gate from closing too quickly and cutting off the end of the desired sound. For example, if a noise gate is used to reduce background noise in a vocal recording, setting a longer hold time can help ensure that the gate does not close before the end of the singer’s words or phrases.

Note: A noise gate is different but similar to an expander.

When To Use A Noise Gate

One of the key benefits of using a noise gate is that it allows you to clean up a recording without affecting the audio you want to hear.

For example, if you are recording a podcast or live-streaming, you may have background noise, such as air conditioning or traffic. A noise gate can help you silence the background noise while still letting your audience hear your microphone when you are speaking into it.

Another common application for a noise gate is when you’re using microphones on a drumset. You don’t want your microphone on your snare drum to hear your floor tom, and you don’t want your floor tom microphone to hear your rack tom. If you use noise gates on these drum microphones, you will only hear each drum when the drummer strikes it, giving you more control and a better audio mix.

When To Avoid Using A Noise Gate

There are a few situations where you may want to avoid using a noise gate or at least use it with caution.

First, if the background noise in your recording is very complex or varied, a noise gate may not be effective at removing it. In this case, you may better use a different type of processing, such as an expander to address the background noise.

Second, if the audio you are trying to preserve is very quiet or has a lot of low-level details, a noise gate can sometimes cause those details to be lost.

Third, if the audio you are trying to preserve has a lot of sudden changes in volume, a noise gate can sometimes cause the audio to sound unnatural or choppy. Depending on the situation, a compressor (or expander) may be a better fit.

Lastly, if your microphone is the only audio source for your podcast, live stream, or voice-over recording, it can add an unnatural feel to your recording. Your quiet moments will sound really “dry” because there is no room tone, and sometimes you can even hear the noise-gate clicking in and out.

Examples Of Noise Gates

Some examples of noise gates include the following:

• A noise gate built into a mixing console or digital audio workstation (DAW) software allows the user to adjust the threshold level and other parameters to control the noise reduction effect.
  • TC-Helicon GoXLR: https://currentprice.io/goxlr
  • Allen & Heath QU16: https://currentprice.io/qu16
  • Most modern digital audio mixers will have a noise gate built-in
• A standalone hardware noise gate can be inserted into the signal chain of an audio system, such as a rack-mounted unit placed between a microphone and a mixer.
  • Drawmer DS201 2-channel Noise Gate: https://currentprice.io/ds201
• A standalone audio plugin with a noise gate can be used with your DAW (Audio software).
  • Nomad Liquid Gate II Noise-Gate Plug-In: https://currentprice.io/liquid_gate
• A noise gate is part of a multi-effect pedal for an electric guitar or another instrument, which allows the user to control the noise reduction.
  • Revv G8 Noise Gate Pedal:
  • ISP Technologies Decimator II Noise Reduction Pedal:
  • Boss NS-2 Noise Suppressor Pedal:

These are just a few examples of noise gates, and there are many other variations and implementations of this audio effect.

Related: What is an Audio Expander?

Noise Gate FAQ

Final Thoughts

A noise gate is a useful tool for cleaning up an audio signal and removing unwanted background noise. You can reduce or eliminate background noise by carefully adjusting the threshold level without affecting the main audio. This can help make your recordings sound more professional and polished and improve the overall quality of your audio.