Even with realtime text, that is where other's letters appear as they type, I find that interruptions don't happen much. I can read while I type much more easily than listen while a talk. The factors I see are fading speed and channel noise... I've heard stories about people talking and listening simultaneously on a telephone, but can't say I've observed it. So my hunch is that fading speed has more to do with it. Anyone know much about interruption in signed conversation?