I seriously have no idea what the name for this electronic instrument is...here are two pictures:

http://en.wikipedia.org/wiki/File:ConradSchnitzler.jpg
http://en.wikipedia.org/wiki/File:Jean-Louis-Costes-Dijon-2009-03.JPG

In both pictures, the thing I'm talking about is the little box with all the jacks sticking out of it. I have seen both Schnitzler and Costes (as well as Merzbow) use these at shows; it seems to me that each connection generates an electronic tone, and what they do is plug in a new jack while unplugging another one to mix the tones together. Sorry if my evidence is inconclusive, this is the best description I can provide.