Audio-Visual Prosody: Perception, Detection, and Synthesis of Prominence

In this chapter, we investigate the effects of facial prominence cues, in terms of gestures, when synthesized on animated talking heads. In the first study a speech intelligibility experiment is conducted, where speech quality is acoustically degraded, then the speech is presented to 12 subjects through a lip synchronized talking head carrying head-nods and eyebrow raising gestures. The experiment shows that perceiving visual prominence as gestures, synchronized with the auditory prominence, significantly increases speech intelligibility compared to when these gestures are randomly added to speech. We also present a study examining the perception of the behavior of the talking heads when gestures are added at pitch movements. Using eyegaze tracking technology and questionnaires for 10 moderately hearing impaired subjects, the results of the gaze data show that users look at the face in a similar fashion to when they look at a natural face when gestures are coupled with pitch movements opposed to when the face carries no gestures. From the questionnaires, the results also show that these gestures significantly increase the naturalness and helpfulness of the talking head.