No matter how well hidden our systems are and how well they do their magic unnoticed in the background, there are times when direct interaction between system and human is a necessity. As long as the interaction can take place unobtrusively and without techno-clutter, this is desirable. It is hard to picture a means of interaction less obtrusive and techno-cluttered than spoken communication on human terms. Spoken face-to-face communication is the most intuitive and robust form of communication between humans imaginable. In order to exploit such human spoken communication to its full potential as an interface between human and machine, we need a much better understanding of how the more human-like aspects of spoken communication work.