It's one of the sounds Codecs make when they are not locked completely. Since I doubt they were using codecs for the sound but satellites instead, that would be my guess. I will try and ask our satellite dude if he heard it and recognized the sound. It was clearly a digital lock kind of error, so it is highly doubtful that it was in the room. The strange thing is that I never heard it on anything but the talk mic. I was pretty involved in a project and only slightly paying attention from the other room though.