The Effect of Embodied Conversational Agents' Speech Quality on Users' Attention and Emotion

This study investigates the influence of the speech quality of Embodied Conversational Agents (ECAs) on users’ perception, behavior and emotions. Twenty-four subjects interacted in a Wizard of Oz (WOZ) setup with two ECAs in two scenarios of a virtual theater partner application. In both scenarios, each ECA had three different speech qualities: natural, high-quality synthetic and low-quality synthetic. Eye gaze data show that subjects’ visual attention was not influenced by ECA’s speech quality, but by their look. On the other hand, subjects’ self-report of emotions and verbal descriptions of their perceptions were influenced by ECAs’ speech quality. Finally, Galvanic Skin Response data were neither influenced by ECAs’ look, nor by their speech quality. These results stress the importance of the correct matching of the auditory and visual modalities of ECAs and give methodological insights for the assessment of user’s perception, behavior and emotions when interacting with virtual characters.