Center channel refers to an audio channel common to many surround sound formats. It is the channel that is mostly, or fully, dedicated to the reproduction of the dialogue of an audiovisual program. The speaker(s) connected to the center channel are placed in the center of and behind the perforated projection screen, to give the effect that sounds from the center channel are coming from the screen. In many home surround sound units, the center channel is positioned above or below the video screen.
In the post-production process of filmmaking and video production sound editing, dialogue can be mapped to other speakers when story action and direction require it, such as when the person talking is off-screen, but it is rare that there is vocal content that is completely absent from the center channel.
In material without accompanying visuals (e.g. music), the center channel simply reproduces sound intended to come from immediately in front of the listener, which usually includes the lead vocals, which are rarely panned hard left or right.
The center channel also anchors the sound field, eliminating phantom images such as those that plagued quadraphonic sound if the speakers were not precisely placed.
The center channel eliminates the need of creating a phantom center with left and right stereo speakers. The center channel provides image stabling effects and is considered the most important channel for film production.