A robot listener for fluent verbal communication

Considers verbal communications between machines and human beings. Speakers may have high psychological stress if the all listeners are not human beings such as computers and so on, because human listeners assist the speaker by nodding and chiming in. Watanabe and Yuuki (1993) showed that such responses of listeners greatly assist fluent verbal communications. On the basis of this result, they proposed a computer listener system in which animation can do nodding and chiming in in place of human listeners. However, computer animations in imaginary two dimensional space may have an essential psychological defect compared with physical existing objects in three dimensional space. This paper tries to make clear this psychological difference quantitatively by several experiments. In the experiments, we adopt a doll as a listener, that has three degrees of freedom in its neck, and it can nod and chime in responding to the speakers words. We evaluate the speaker´s psychological stress by heart rate, blood pressure and so on