Angela Tinwell

With increasing sophistication of realism for human-like characters within computer games, this chapter investigates player perception of audio-visual speech for virtual characters in relation to the Uncanny Valley. Building on the findings from both empirical studies and a literature survey, a conceptual framework for the uncanny and speech is put forward which includes qualities of speech sound, lip-sync, human-likeness of voice, and facial expression. A cross-modal mismatch for the fidelity of speech with image can increase uncanniness and as much attention should be given to speech sound qualities as aesthetic visual qualities by game developers to control how uncanny a character is perceived to be.

This paper presents a study of how exaggerated facial expression in the lower face region affects perception of emotion and the Uncanny Valley phenomenon in realistic, human-like, virtual characters. Characters communicated the six basic emotions, anger, disgust, fear, sadness and surprise with normal and exaggerated mouth movements. Measures were taken for perceived familiarity and human-likeness. The results showed that: an increased intensity of articulation significantly reduced the uncanny for anger; yet increased perception of the uncanny for characters expressing happiness with an exaggeration of mouth movement. The practical implications of these findings are considered when controlling the uncanny in virtual characters.