A voice-over is a narration that is played on top of a video segment, usually with the audio for that segment muted or lowered.
In works of fiction, the voice-over is often by a character reflecting back on his or her past, or by a person external to the story who usually has a more complete knowledge of the events in the film than the other characters. The genre of film noir is especially associated with the voice-over technique. Also, directors may add a voice-over late in the production because the plot or a character's motivation isn't clear; for instance Francis Ford Coppola added Capt. Willard's voice-overs to Apocalypse Now to clarify Willard's character.
The voice-over has many applications in non-fiction as well. Television news is often presented as a series of video clips of newsworthy events, with voice-over by the reporters describing the significance of the scenes being presented; these are interspersed with straight video of the news anchors describing stories for which video is not shown. Live sports broadcasts are usually shown as extensive voice-overs by expert announcers over video of the sporting event. Game shows formerly made extensive use of voice-overs to introduce contestents and describe available or awarded prizes, but this technique has diminished as shows have moved toward predominantly cash prizes.
The voice-over may be spoken by someone who also appears on-screen in other segments or it may be performed by a specialist voice actor.
