Video Voice Over
Video Voice-over describes the technique by which any disembodied voice is broadcast live or pre-recorded in radio, theater, industrial shows, fashion shows, presentations, television commercials, television programs, animation and live-action films.
More specifically in film, the filmmaker places the sound of a human voice (or voices) over images shown on the screen. These sounds may or may not be related to the images being shown. Sometimes voiceovers can create ironic counterpoint with the images being shown; also, sometimes they can be random voices not directly connected to the people seen on the screen.
Thus, the video voice-over becomes the narration that is played on top of a video segment, usually with the audio for that segment muted or lowered - or not existing at all in the case of many documentary films.
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 contestants and describe available or awarded prizes, but this technique has diminished as shows have moved toward predominantly cash prizes.
The commercial use of voice-over in advertising has been popular since the beginning of radio. In the early years, before effective sound recording, announcers were live in a studio with the rest of the cast, crew and, usually, orchestra. A corporate sponsor hired a producer, who hired writers and voice-actors to perform comedy or drama. The industry expanded very rapidly with the advent of television in the 1950's and the age of highly produced serial radio shows ended. The ability to record high-quality sound on magnetic tape also created opportunities.
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. Voice-over is also commonly referred to as off camera commentary.
Voice-over commentary by a leading critic, historian, or by the production personnel themselves is now a prominent feature of the release of films on DVDs.