Digital audio and video files are created corresponding to selected scenes from a creative production and are provided with a processing system that enables dialog to be selected from a scene and replaced by a user's dialog which is automatically synchronized with the original dialog so as to be in synchronism with lip movements displayed by the accompanying video display. The processing further includes a graphical user interface that presents the user with the video, the text of the dialog, and cues for rehearsal and recording of replacement dialog by the user. Replay of the user's dialog is accompanied by the video and part of the original audio except that the original dialog corresponding to the user's dialog is muted so that the user's dialog is heard as a replacement. Singing or other sounds associated with visible action may also be replaced by the same processes.