Syntact

Check this thing out!

By directing a series of ultrasonic jets, it lets the user manipulate sound in a tactile manner previously unimagined in spacial midi control.

It looks kind of like a theremin to use, combined with erm .. a powerglove? haha

Control input:
Syntact™ is operated via optical hand-gesture analysis. An integrated USB camera is used to analyze the hand position in the focal point region of the instrument. Sophisticated image descriptors are then extracted in real-time and converted to MIDI data, which can further be used to drive any desired sound synthesis/processing parameters in any audio production software or hardware environment.

Tactile feedback:
The feedback section of the instrument uses the analog audio output of any software or hardware synthesizer, instrument, sequencer or any kind of audio generator. It uses the audio signal to compute an ultrasound signal mixture that reflects the harmonic and temporal characteristic of the given audio signal. The ultrasound signal mixture is projected through an annular array of 121 ultrasonic transducers, focusing all the acoustic energy in one spot (the focal point).

http://www.ultrasonic-audio.com/products/syntact.html