The term voice-over refers to a production technique where a non-diegetic voice is broadcast live or pre-recorded in radio, television, film, theatre and/or presentation. 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.
The term voice-over can also refer to the actual voice actor who performed the recording. The terms voice actor, narrator, voice artist, and announcer are all similarly used.
In the 1956 film version of Herman Melville's Moby-Dick, Richard Basehart, as Ishmael, narrates the story and sometimes comments on the action in voice-over, as does William Holden in the films Sunset Boulevard and The Counterfeit Traitor, as well as John Mills in David Lean's Great Expectations (based on Charles Dickens's novel) and Michael York in a television remake of the book.
Voice-over technique is likewise used to give voices and personalities to animated characters. Among the most noteworthy and versatile of whom include Mel Blanc, Daws Butler, Don Messick and June Foray.
In film, the film-maker places the sound of a human voice (or voices) over images shown on the screen that may or may not be related to the images being shown. Consequently, voice-overs are sometimes used to create ironic counterpoint. Also, sometimes they can be random voices not directly connected to the people seen on the screen. 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.
Voice-overs are often used to create the effect of storytelling by a character/omniscient narrator. For example, in The Usual Suspects, the character of Verbal Kint has voice-over segments as he is recounting details of a crime. Other examples of storytelling voice overs can be heard in Gattaca, Blade Runner, The Shawshank Redemption, Big Fish, Moulin Rouge! and Goodfellas.
Sometimes, voice-over can be used to aid continuity in edited versions of films, in order for the audience to gain a better understanding of what has gone on between scenes. This was done when the 1948 Joan of Arc, starring Ingrid Bergman, turned out to be far from the box-office and critical hit that was expected, and was edited down from 145 minutes to 100 minutes for its second run in theatres. The edited version, which circulated for years, used narration to conceal the fact that large chunks of the film had been cut. In the full-length version, restored in 1998 and released on DVD in 2004, the voice-over narration is heard only at the beginning of the film.
The genre of film noir is especially associated with the voice-over technique.
In radio, voice-overs are an integral part of the success of the radio programme. Although the announcer holds the prestige and claims all the glory, it is the voice-over artist that is the real drive behind the show. For example, David M. Green's Summer Pow-Wow http://www.davidmgreen.com and his voice-over artist, Tim Wray.
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.
Voice-over commentary by a leading critic, historian, or by the production personnel themselves is often a prominent feature of the release of feature films or documentaries on DVDs.
The commercial use of voice-over in advertising has been popular since the beginning of radio broadcasting.
In the early years, before effective sound recording and mixing, announcements were produced "live" and at-once in a studio with the entire 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 1950s and the age of highly produced serial radio shows ended. The ability to record high-quality sound on magnetic tape also created opportunities, as has the proliferation of home computers capable of recording, often using inexpensive (even free) software and a microphone of reasonable quality.
In some countries, such as Russia and Poland, a voice-over provided by a single artist is commonly used on television as a localization technique, as an alternative to full dubbing. See Gavrilov translation.