Noise gates are commonly used in music production, live sound reinforcement, and broadcast applications to suppress unwanted background noise and improve overall sound quality. They are particularly useful for reducing unwanted noises such as hum, hiss, and buzz, which are especially audible when the singer\/speaker pauses. <\/p>\n\n\n\n
As a practical example, you record yourself singing at home with a microphone<\/a>, and because your room is not completely isolated from the outside world, you can hear traffic on the street in the background. This background noise is not very loud, and when you sing, it is masked by your singing and is not audible. But you can hear it during breaks.<\/p>\n\n\n\n Now you have two options: You can cut every single break, which is a lot of work, or you can use a noise gate. It turns on when you stop singing and suppresses traffic noise, hissing, humming, and the like.<\/p>\n\n\n\n Noise gates are basically compressors that work from a certain threshold, only in reverse. They start working when the signal falls below a certain volume and then reduce the volume by a certain ratio. This ratio often goes to infinity, i.e. the signal is completely suppressed.<\/p>\n\n\n\n While singing or playing, the signal level should be above the adjustable threshold. As soon as you stop playing or singing, the signal level will drop below the set threshold.<\/p>\n\n\n\n At this point, the Noise Gate kicks in and suppresses the entire signal, which at this point is just noise. As soon as the vocalist starts singing again, the noise gate stops working. However, the audio signal will be so much louder than the noise that it will no longer be noticeable.<\/p>\n\n\n\n With a noise gate, you can only remove the noise in the pauses, not the noise in the singing or playing. If the noise is loud enough to be heard during the performance, it is better to re-record, and if that is not possible, work with specialized audio repair software such as iZotope RX<\/a>. These may be able to fix the problem, but it is always best to re-record.<\/p>\n\n\n\n Most noise gate plugins have similar parameters. Hardware noise gates usually have fewer features, because e.g. the lookahead can only be done digitally.<\/p>\n\n\n\n First, place the Noise Gate plugin in an insert slot on the track where you want to reduce noise. It should be the very first plugin in the chain, otherwise other effects will reduce its effectiveness.<\/p>\n\n\n\n For example, using a compressor in front of the noise gate reduces the level difference between the signal and the noise, because the noise gets louder as the signal is compressed. This makes adjusting the noise gate much more difficult and inaccurate.<\/p>\n\n\n\n If the VST plugin<\/a> offers the option, be sure to enable Lookahead. This gives the plugin a \"look into the future\" and allows it to open the noise gate just before the signal starts to ensure that the initial level is not cut off.<\/p>\n\n\n\n I also always choose the maximum lookahead time to make sure nothing is missing.<\/p>\n\n\n\n This is probably the most important step of all. The threshold should be set just above the noise and as far below the actual signal as possible.<\/strong> This ensures that the quieter parts of the performance are not cut off (e.g. with vocals, the beginning and end of a movement are often slightly quieter).<\/p>\n\n\n\n Most plugins offer a visual aid to help you distinguish the noise from the signal. It is always better to double-check that the noise gate is not removing quiet parts of the signal that you actually want.<\/p>\n\n\n\n The Attack parameter determines how long it takes for the gate to open when the signal rises above the threshold. If you want to preserve the natural sound of the audio track, you should always use very fast attacks, in most cases even 0.<\/strong><\/p>\n\n\n\n Slower attack times cut off the initial transients, which can sometimes be desirable, but in most cases is not - it results in an unnatural sound.<\/p>\n\n\n\n The next step is to set the release time, which is the time it takes for the Noise Gate to close at the end of the performance. You should always start with long release times,<\/strong> so that the last syllables or notes are not cut off, and then slowly reduce the release times until you are satisfied.<\/p>\n\n\n\n Care should always be taken not to lose the final accents of the performance, as they often contain important information that, if missing, will result in an unnatural sound. For example, the last breath or air on \"t\" or \"s\" in a vocal performance. <\/p>\n\n\n\n So remember:<\/strong> Always listen carefully to what's happening throughout the track, don't just set it once and forget it.<\/p>\n\n\n\n This step is optional, but the Hold parameter can be used to fine-tune the rate at which the Noise Gate closes. For example, if the last parts of the performance are cut off even with a long Release time, you can use a longer Hold time to bring those parts back. Hold works like a pre-release.<\/p>\n\n\n\n The next step is to decide how much to reduce the background noise. High ratios such as 100:1 or \u221e:1 should be selected if complete noise reduction is desired. If all other parameters are set correctly, a natural sound should be maintained.<\/p>\n\n\n\n However, if the audio track is difficult or you simply don't want to remove all the noise, you can select lower ratios, from 4:1 to 50:1. The Range parameter can be used to set an absolute limit for the level reduction.<\/p>\n\n\n\n Most noise gates have a few extras like sidechain and filters that can be helpful in some situations:<\/p>\n\n\n\n With the high-pass filter<\/a> <\/strong>or a low-pass filter<\/strong>, you can tell the Noise Gate to ignore certain frequencies so that it won't open. For example, you might put a noise gate on the kick track to suppress snare bleed. Then you set the low-pass filters in the noise gate so that snare hits don't open the gate at all, and it only opens on a kick hit.<\/p>\n\n\n\n The sidechain control<\/strong> lets you set the Noise Gate to open only when another track crosses the threshold. For example, the bass drum in your production needs more bass. Record a bass synthesizer with a long note and place it under the bass drum. Place a noise gate with the kick drum as a sidechain input on top of the bass synth. This way, the synthesizer starts and stops in sync with the kick and overlays perfectly.<\/p>\n\n\n\n When recording vocals with microphones, there is always some noise because you have to give the preamp<\/a> a lot of gain. This amplifies the inherent noise of the microphone, but with a well adjusted noise gate (as described above) this noise can be well suppressed.<\/p>\n\n\n\n The same applies to recording all other instruments with a microphone, but the instruments are usually so loud that the noise is not audible because less amplification is needed.<\/p>\n\n\n\n A noise gate allows you to manipulate the dynamics\/transients of the audio track, similar to a compressor. For example, the snare drum's reverberation can be extremely shortened, as you can hear here:<\/p>\n\n\n\nHow does a noise gate work?<\/h3>\n\n\n\n
![\"Functionality](\"https:\/\/woodandfirestudio.com\/wp-content\/uploads\/2023\/04\/Noise-GateEN.jpg\" "\\"\\"")
A noise gate cannot remove all background noise<\/h3>\n\n\n\n
Parameters of a noise gate<\/h3>\n\n\n\n
![\"The](\"https:\/\/woodandfirestudio.com\/wp-content\/uploads\/2023\/04\/NoiseGB.jpg\" "\\"\\"")
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How to get the most out of your noise gate<\/h3>\n\n\n\n
1. Insert a Noise Gate as the first insert plugin<\/h4>\n\n\n\n
2. Activate lookahead<\/h4>\n\n\n\n
3. Set the threshold<\/h4>\n\n\n\n
![\"Setting](\"https:\/\/woodandfirestudio.com\/wp-content\/uploads\/2023\/04\/threshhold.jpg\" "\\"\\"")
4. Set attack<\/h4>\n\n\n\n
5. Set release<\/h4>\n\n\n\n
6. Set hold <\/h4>\n\n\n\n
7. Determine ratio and range<\/h4>\n\n\n\n
8. Extras<\/h4>\n\n\n\n
![\"Sidechain](\"https:\/\/woodandfirestudio.com\/wp-content\/uploads\/2023\/04\/sidechainsektion.jpg\" "\\"\\"")
Practical application examples for a noise gate<\/h3>\n\n\n\n
Reduction of background noise in vocal recordings<\/h4>\n\n\n\n
Transient processing<\/h4>\n\n\n\n