Always fascinated to see people use alternate input methods. I wonder if there is some possibility for steganographic applications with this? I.E., plug a soundcard into an oscilliscope, play a specially crafted .wav or equivalent file, and viola, secret message?
He used framework called Pure Data to build the sounds by additive synthesis (of pure sine waves). If you do that with some care (and you can pick the phases of the sine waves freely), you can build/explore/craft some pretty funky visuals quite easily, I imagine. It's the large scale composition, making it into a coherent whole that seems hardest to me (then, that is always my weak point when making music, I'll just keep practising :) )
