Editing Noise gate (section)

{{short description|Audio processing device}}
{{Use dmy dates|date=December 2019}}

[[File:Alesis Micro Gate 9006.jpg|thumb|An Alesis Micro Gate noise gate]]

A '''noise gate''' or simply '''gate''' is an [[electronic device]] or software that is used to control the [[amplitude|volume]] of an [[audio signal]]. Comparable to a [[limiter]], which attenuates signals ''above'' a threshold, such as loud attacks from the start of musical notes, noise gates attenuate signals that register ''below'' the threshold.<ref>Hodgson, Jay (2010). ''Understanding Records'', p. 86. {{ISBN|978-1-4411-5607-5}}.</ref> However, noise gates attenuate signals by a fixed amount, known as the range. In its simplest form, a noise gate allows a main [[signal]] to pass through only when it is above a set threshold: the gate is ''open''. If the signal falls below the threshold, no signal is allowed to pass (or the signal is substantially attenuated): the gate is ''closed''.<ref>{{Cite book
  | last = Davis
  | first = Gary
  | last2 =  Jones
  | first2 =  Ralph
  | last3 = Yamaha International Corporation
  | title = The Sound Reinforcement Handbook 
  | publisher = Hal Leonard
  | year = 1989
  | isbn = 0-88188-900-8
  }}.</ref> A noise gate is used when the level of the signal is above the level of the unwanted [[noise]]. The threshold is set above the level of the noise, and so when there is no main signal, the gate is closed. 

A common application is with electric guitar to remove hum and hiss noise caused by distortion [[effects unit]]s. A noise gate does not remove noise from the signal itself; when the gate is open, both the signal and the noise will pass through. Even though the signal and the unwanted noise are both present in open gate status, the noise is not as noticeable. The noise becomes most noticeable during periods where the main signal is not present, such as a bar of rest in a [[guitar solo]]. Gates typically feature attack, release", and hold settings and may feature a look-ahead function.<ref>Hodgson (2010), p. 87.</ref>

[[File:Noise Gate Attack Hold Release.svg|thumb|400px|right|The attack, hold, and release functions of a noise gate]]