Abstract
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.