· By Jan Branicki

Noise Gates: What They Are and How They Work?

If you've ever battled with distracting noise overshadowing your music or audio projects, you know the frustration all too well. That unwanted hum, hiss, or background noise can quickly diminish the clarity and impact of your work.

Luckily, there's a simple and effective solution: noise gates. In this article, we'll explore what noise gates are, how they work, and their various applications. So let’s dive right in!

What Are Noise Gates?

A noise gate is an audio processing tool that controls undesired noise in audio recordings or live sound setups. As the name suggests, it's like a virtual gate, allowing desired audio signals to pass through while silencing the unwanted noise.

You can see noise gates in action in various areas of audio production, including recording studios, live performances, and even in-home setups. 

Importance and Usage of Noise Gates

Noise gates play a crucial role in various fields, including music production, broadcasting, podcasting, and live sound engineering. Here are the importance and usage of noise gates in audio production:

  • Noise Reduction: Noise gates remove background noise such as microphone bleed, ambient sounds, or electrical interference resulting in cleaner recordings.
  • Vocal Clarity: Noise gates improve vocal recordings by eliminating breath sounds and low-level noise during silent passages.
  • Drum Control: They enhance drum recordings by managing sustain and reducing unwanted ringing or bleed.
  • Creative Effects: Noise gates can create rhythmic patterns and dynamic gating effects in audio production. This technique is often used in electronic music genres and can help bring a sense of movement and groove to a track.
  • Sound Design: They are valuable tools for shaping sound envelopes and creating unique effects in sound design.

What Are Noise Gates

By mastering the usage of noise gates, you can take your audio productions to new levels of quality and clarity.

Elements of Noise Gates

If you’ve used compressors before, you already know that noise gates have four main elements.

1. Threshold

The threshold in a noise gate acts as a control point that determines when the gate opens or closes. By setting the threshold just above the background noise level, the gate allows desired signals to pass through while muting any audio below that threshold. 

This ensures that intended sounds are preserved while unwanted noises are removed.

2. Attack Time

Attack time in noise gates determines how quickly the gate opens when the audio signal exceeds the threshold. It controls the response speed of the gate and maintains a clean audio signal. A shorter attack time enables an immediate gate opening, while a longer attack time facilitates a more gradual gate opening.

3. Hold Time

Hold time in noise gates determines how long the gate remains open after the audio falls below the threshold. It prevents premature gate closure during momentary pauses, ensuring consistent audio presence. Shorter times allow quicker closure, while longer times sustain the audio before fully closing.

4. Release Time

Release Time in noise gates determines how quickly the gate closes after the audio falls below the threshold. Shorter release times result in instant gate closure and abrupt audio cutoff, while longer release times let the signal fade out gradually once it falls below the threshold. It controls the duration before the unwanted sound is fully muted.

Applications of Noise Gates in Audio Production

Here are some practical applications of noise gates in different aspects of audio production.

Vocals

In the case of vocals, noise gates can filter out unwanted sounds and improve the recording's overall clarity. It is often advisable to position the noise gate before reverbs or delays to prevent these effects from amplifying any residual noise.

Guitar

Noise gates are important in guitar production because they keep heavily distorted guitar tones clean and clear. They help reduce string noise caused by finger and hand movements when placed before or after the equalizer. 

This application is particularly valuable in music styles like metal and rock, where precise and aggressive guitar playing is essential.

How Do Noise Gates Work

Drums

Drum recordings often capture unwanted room ambiance and bleed from other instruments. To reduce these undesirable sounds and create a cleaner foundation for further processing, noise gates can be used at the beginning of the signal chain for drums. 

During the mixing stage, the engineer has more control over the drum sound because they can effectively filter out room sounds and other frequencies.

Podcasting and Voiceover: 

Noise gates are also very useful for podcasting and voiceover work, where getting a clean, professional-sounding voice recording is the most important thing. 

By positioning the noise gate carefully after the microphone preamp and any required EQ or processing, you can effectively remove background noise, room tone, and other low-level sounds.

Do Noise Gates Affect Tone?

Indeed, noise gates have an impact on tone. They can alter the way notes fade out and influence your playing experience. To preserve the desired tone and feel, it is essential to carefully set the gate parameters, avoiding excessive cutoffs that could adversely affect your instrument or audio signal.

How Do Noise Gates Work?

Noise gates work by controlling audio signals based on a set threshold. The gate opens when the audio signal exceeds the threshold, allowing the desired audio to pass through. When the audio signal falls below the threshold, the gate closes, reducing or muting unwanted noise. 

You can customize how the gate works by changing settings like attack time, release time, and hold time. These settings let you control how quickly the gate responds and how it processes the audio. 

Adjusting these settings reduces unwanted noise and maintains the desired audio quality in different production situations.

How to Use a Noise Gate in Your Mixes? A Step-by-Step Guide

Here are four straightforward steps to guide you through the process of using noise gates effectively:

  1. Record the Audio Track: Try to target an approximate audio level of -12 dB, which is a common goal for many recording engineers. If you’ve already recorded the audio track, ensure it has a healthy signal level without clipping or excessive noise.
  2. Insert a Noise Gate Plugin: Next, insert a noise gate plugin into the corresponding audio track in your digital audio workstation (DAW). Most DAWs provide built-in noise gate plugins, or you can use third-party plugins for more advanced features.
  3. Set the Threshold: After that, you must set the threshold just above the background noise level or unwanted sound. Be careful not to set it too high, as it may cause the gate to cut off desired audio.
  4. Set the Attack and Release Parameters: Experiment with different attack and release times to find the perfect setting for your audio. Optimal values depend on the specific audio material and desired effect, but ideally, you could start with an attack time of 20 milliseconds and a release time of 400 milliseconds.

Do Noise Gates Affect Tone

Final Thoughts

In conclusion, noise gates are powerful tools in audio production, helping you eliminate unwanted noise and maintain clear recordings. By adjusting the threshold, attack time, hold time, and release time, you can customize the gating effect to suit your needs. 

So, whether you're working on vocals, guitars, drums, or podcasting, try using noise gates to get clean and professional audio recordings.