A shoe-based interface is presented, which enables users to play percussive virtual instruments by tapping their feet. The wearable interface consists of a pair of sandals equipped with four force sensors and four actuators affording audiotactile feedback. The sensors provide data via wireless transmission to a host computer, where they are processed and mapped to a physics-based sound synthesis engine. Since the system provides OSC and MIDI compatibility, alternative electronic instruments can be used as well. The audio signals are then sent back wirelessly to audio-tactile exciters embedded in the sandals' sole, and optionally to headphones and external loudspeakers. The round-trip wireless communication only introduces very small latency, thus guaranteeing coherence and unity in the multimodal percept and allowing tight timing while playing.
