Getting rid of background noise or that annoying headphone spill can be a nightmare to deal with.
Noise...noise is everywhere and can creep up on you unannounced even in the pristine clear digital realm. In fact noise is exposed even further because of the purity of the digital realm.
The most common forms of noise are microphone related. Headphone spill which is the microphone picking up the headphone over-spill is the most common form of noise that plagues mic recordings. Background noise - anything from the room, outdoors or even the singer moving around and knocking the stand are termed as noise as they are printed on the recording. Now imagine countless channels of mic recordings all playing at the same time in your mix. The noise sums in exactly the same way that 'clean' audio does.
To get rid of noise we use a process that has remained unchanged since inceptions. It is the Noise Gate.
A Gate is a device or plugin that behaves like a downward expander with infinite ratio. A downward compressor processes the signal that exceeds the threshold. A gate processes the signal that falls BELOW the threshold. When the signal falls below the threshold it is attenuated or silenced. The gate opens as the signal rises above a threshold, and closes when it falls below it. How this is achieved is determined by the various features gates offer.
Attack and Release determine how the gate closes and open.
Some gates offer a hold feature which keeps the gate open for a specified time and prevents 'chattering' (the gate opens and closes rapidly in succession).
Some gates will work in either Peak or RMS Mode.
Range determines by how much the signal is attenuated. This is often used to avoid abrupt closing/opening. It allow for a smoother transition.
Some gates have side-chaining which helps to fine tune the gate's behaviour.
This video tutorial runs through the process step by step and with using different Noise Gates.
Topics covered in this video are:
What is a Gate, what are its features, how do you use them
Hold, Attack and Release
Peak and RMS