Spatial Sounds (100dB at 100km/h) is an interactive audio installation by Marnix de Nijs and Edwin van der Heide. In this engine-powered installation, a speaker is mounted onto a rotating arm that is several meters long. Like a watchdog, the machine scans the surrounding space for visitors. Closer investigation would be tempting fate, with the rotating arm swinging so powerfully round. You hear the impressive sound of the mighty motor revving up, turning faster and faster. You can feel the displacement of air as the speaker whizzes past you, and you had better step back, out of reach. The machine slows down and, when the shock wears off, you start exploring the space, with your movements manipulating the sound it produces. Just don’t get too close! Spatial Sounds (100dB at 100km/h) builds up a physically tangible relationship with the visitor, since it is the game of attracting and repelling between machine and visitor that determines its sound and movement.