Editing Sound reinforcement system (section)

===In-ear monitors===
[[Image:InEarMonitors.jpg|thumb|right|200 px|A pair of universal fit [[in-ear monitor]]s. This particular model is the Etymotic ER-4S]]
[[In-ear monitor]]s are headphones that have been designed for use as monitors by a live performer. They are either of a ''universal fit'' or ''custom fit'' design. The universal fit in-ear monitors feature rubber or foam tips that can be inserted into virtually anybody's ear. Custom-fit in-ear monitors are created from an impression of the user's ear that has been made by an [[audiologist]]. In-ear monitors are almost always used in conjunction with a wireless transmitting system, allowing the performer to freely move about the stage while receiving their monitor mix.

In-ear monitors offer considerable isolation for the performer using them: no on-stage sound is heard and the monitor engineer can deliver a much more accurate and clear mix for the performer. With in-ear monitors, each performer can be sent their own customized mix; although this was also the case with monitor speakers, the in-ear monitors of one performer cannot be heard by the other musicians. A downside of this isolation is that the performer cannot hear the crowd or the comments from other performers on stage that do not have microphones (e.g., if the bass player wishes to communicate to the drummer). This has been remedied in larger productions by setting up microphones facing the audience that can be mixed into the in-ear monitor sends.<ref name="in-ear tips" />

Since their introduction in the mid-1980s, in-ear monitors have grown to be the most popular monitoring choice for large touring acts. The reduction or elimination of loudspeakers other than instrument amplifiers on stage has allowed for cleaner and less problematic mixing for both the front of house and monitor engineers. Audio feedback is greatly reduced and there is less sound reflecting off the back wall of the stage out into vocal mics and the audience, which improves the clarity of the front-of-house mix.