Various three-dimensional (3-D) talking heads have been developed lately for language learning, with both external and internal articulatory movements being visualized to guide learning. Mandarin pronunciation animation is challenging due to its confusable stops and affricates with similar places of articulation. Until now, less attention has been paid to the biosignal information of aspiratory airflow, which is essential in distinguishing Mandarin consonants. This study fills a research gap by presenting the quantitative analyses of airflow, and then designing an airflow model for a 3-D pronunciation system. The airflow information was collected by Phonatory Aerodynamic System, so that confusable consonants in Mandarin could be discerned by mean airflow rate, peak airflow rate, airflow duration, and peak time. Based on the airflow parameters, an airflow model using the physical equation of fluid flow was proposed and solved, which was then combined and synchronized with the existing 3-D articulatory model. Therefore, the new multimodal system was implemented to synchronously exhibit the airflow motions and articulatory movements of uttering Mandarin syllables. Both an audio-visual perception test and a pronunciation training study were conducted to assess the effectiveness of our system. Perceptual results indicated that identification accuracy was improved for both native and nonnative groups with the help of airflow motions, while native perceivers exhibited higher accuracy due to long-term language experience. Moreover, our system helped Japanese learners of Mandarin enhance their production skills of Mandarin aspirated consonants, reflected by higher gain values of voice onset time after training.

The 3D talking head has been developed fast, in which both external and internal articulators were demonstrated. For Mandarin pronunciation, the aspiration airflow is crucial to discriminate confusable Mandarin consonants. In this paper, we present a 3D talking head system for articulatory and aspiration animation with the use of EMA articulation data and airflow data simultaneously. The quantitative analyses of airflow data indicated confusable Mandarin consonants could be distinguished from each other by the mean airflow during voicing, peak expiratory airflow, and airflow duration. An airflow model was then incorporated into the 3D articulatory model to produce the airflow in accordance with articulator movements of Mandarin pronunciation. An audio-visual test was designed to evaluate the current 3D articulation and aspiration system, where minimal pairs were used to recognize the animation. The identification accuracy was significantly improved from 43.9% without airflow to 84.8% with airflow-incorporated information.

17th Annual Conference of the International Speech Communication Association, INTERSPEECH 2016, San Francisco, US, 8-16 September 2016

17th Annual Conference of the International Speech Communication Association, INTERSPEECH 2016, San Francisco, US, 8-16 September 2016