Developing embodied agents for education applications with accurate synchronization of gesture and speech

Abstract

Embodied agents have great potential for education field, which are promising to maximize the learner’s learning gains and enjoyment. In many education applications, multimodal representation of embodied agents is a powerful approach for obtaining the above benefit, which requires accurate synchronization of gesture and speech. For this purpose, we investigate the important issues in synchronization as a practical guideline for our algorithm design through a precedent case study and propose a two-step synchronization method. Our case study reveals that two issues (i.e. duration and timing) play an important role in synchronizing of gesture with speech. Considering the synchronization problem as a motion synthesis problem instead of a behavior scheduling problem used in the conventional methods, we employ a motion graph technique with constraints on gesture structure for coarse synchronization in a first step and refine this further by shifting and scaling the gesture in a second step. Subjective evaluation has demonstrated that the proposed method achieves more accurate synchronization with respect to both duration and timing, and higher motion quality than the stateof-the-art methods. Furthermore, we have implemented the proposed synchronizationmethod in an authoring tool for education applications. We have conducted several experiments in a university, whose results have demonstrated that our system makes the creation of attractive animations easier and faster (only about 10% operation time) than manual creation of equal quality, and it is effective to use embodied agents in education applications.