Spatial Sounds (100dB at 100km/h) is an interactive installation that is capable of very intelligent behavior. Not only can the arm spin quickly or slowly, it can also make very well-defined movements in both directions. On the one hand, Spatial Sounds (100dB at 100km/h) lives a life of its own; on the other, it reacts very directly to the people in its space. The sensor can detect how close the visitors are and where they are in relation to the arm. When the installation scans the space, it makes inspecting movements and generates sounds that symbolize this scanning. It produces remarkably short, loud pulses and ‘listens’ to the reverberations from the empty space. The pulses combine different frequency ranges and rhythmical patterns. When visitors enter the room, they are detected immediately. The installation reacts in both a musical and a gestural way. The sounds relate directly to both the position of the arm and the dynamic ‘map’ of the space and the visitors. These sounds are very physical. For example, when the speaker is pointing at someone, it will generate a specific sound. This is also the case at high speeds and with several people in the room. However, the sounds and movements of the arm also tempt visitors to move around. Different locations in the space represent different sounds, as does the distance of the visitors to the rotating arm.