The IR Drum box is part of a larger set of Intonarumori boxes we built. Check them all out at http://urbanstew.org/projects/intonarumori-noise-machines/
This completed box is played by moving your hands in front of four different IR sensors (two sensors on the top of the box and one on each side). The sounds are best triggered when users play them like air drums. The different sensors correspond to different types of drums.
This video documents one of the earlier prototyping stages of the Drum Box.