Disclosed is a technique for a multimedia authoring tool embodied in a computer program. A voice clip is displayed on a timeline, and a playback time point for each syllable and pronunciation information of the corresponding syllable are also displayed. Also, a motion clip may be edited in synchronization with the voice clip on the basis of the playback time point for each syllable. By moving a syllable of the voice clip along the timeline, a portion of the voice clip may be altered.