A sonorization consists of recording a sound on a totally mute image or recording a sound on an image that although it already has ambient sound, it is defective or must be replaced. The sonorizations are usually performed in dubbing studios. A sonorization differs from a dub in which the actor does not a picture, while in the dubbing itself. Many Spanish films have sound effects because the director demands it, the actors do not have a good diction and must be improved by a dubbing actor, or because more sound effects are needed and the recording of these is necessary.
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