Peacock is a newly designed interface for improvisational performances. The interface is equipped with thirty-five proximity sensors arranged in five rows and seven columns. The sensors detect the movements of a performer’s hands and arms in a three-dimensional space above them. The interface digitizes the output of the sensors into sets of high precision digital packets, and sends them to a patch running in Pdextended with a sufficiently high bandwidth for performances with almost no computational resource consumption in Pd. The precision, speed, and efficiency of the system enable the sonification of hand gestures in realtime without the need to attach any physical devices to the performer’s body. This paper traces the interface’s evolution, discussing relevant technologies, hardware construction, system design, and input monitoring.