"I have always been interested in ultrasound, and that species are able to listen in that range creates interesting areas of research for audio artists. BAT CAGE is a microphone recording in a room of an ultrasound composition in the range of 40 to 90.000 Hz. I am aware of tech nerds making a problem out of the limited frequency range of microphones, computers, and sound equipment, You may also bother me with Nyquist and other superficial details. However, as an artist I would never let technology be in the way of a piece of art!"