Varèse designed a very complex spatialization scheme which was synchronized to the film. Prefiguring the acousmonium style of sound projection, hundreds of speakers were controlled by sound projectionists with a series of rotary telephone dials. Each dial could turn on five speakers at a time out of a bank of 12. Many estimates of the pavilion's sound system go as high as 450 speakers, but based on the limitations of the switching system and the number of projectionists used, an estimate of 350 seems more reasonable.