Each of the three subjects is equipped with a head mount display and a sensor system and enters a dark five-meter square. In this space, their heartbeats are converted into audible pulses and visible globular shapes of computer graphics, and these are the only signals that make the position of another person perceptible. The subjects become aware of space existing between themselves and other persons, not by way of their physical appearance or voice but in the form of virtual space made visible and audible.