A pair of pickup antennas are also mounted on the floor of the chair platform, and are used to similarly measure the proximity of left and right feet, providing a set of pedal controllers. In order for a performer to use these sensors, he must be seated in the chair, and thus coupled to the transmitting antenna. Other performers may also inject signal into the pickup antennas if they are touching the skin of the seated individual, thus becoming part of the extended antenna system. These are used for changing parameters when the foot pedals are dedicated to generating musical sounds, or for instigating t riggers when the performer is not seated, hence is unable to use the sensors. The sensors are used to trigger and shape sonic events in several different ways, depending on the portion of the composition that is being performed.
Several modes produce audio events that are also sensitive to the velocity of the hands and feet.