heatre playback systems should provide a stable aural image for as many audience members as possible and allow for the movement of such images during playback. The system should also allow the sound designer to control the location of each sound cue while other cues play concurrently. Ideally the sound system could create aural images for each cue anywhere within the theatre and perhaps also imply positions outside the lintits of the theatre space. Within this general principle it is singularly important that sound systems be able to generate aural images which are synchronized to visual images on tile stage, allowing the natural assumption in the audience's mind that the aural and visual worlds of the play are one. 12 WIN T E R I 9 9 9 TZ,&T