Voice-over is a production technique whereby a voice which is not part of the narrative (non-diegetic) is used in a radio, television production, filmmaking, theatre, or other presentations. The voice-over may be spoken by someone who appears elsewhere in the production or by a specialist voice talent.
Voice-over translation is a common requirements in different media. For classical movies the sound is normally voiced by at least four actors. The voice artists try to match the original voice and preserve the intonation. The main reason for the use of this type of translation is that unlike synchronized voice translation, it takes a relatively short time to produce as there is no need to synchronize the voices with the character's lip movements, which is compensated by the quieted original audio. When there is no speaking in the film for some time, the original sound is turned up.