A pronunciation training system for Japanese lexical accents with corrective feedback in learner's voice

A system was developed for teaching non-Japanese learners pronunciation of Japanese lexical accents. The system first identifies word accent types in a learner's utterance using F0 change between two adjacent morae as the feature parameter. As for the representative F0 value for a mora, we defined one with a good match to the perceived pitch. The system notices the user if his/her pronunciation is good or not, and, then, generates audio and visual corrective feedbacks. Using TDPSOLA technique, the learner's utterance is modified in its prosodic features by referring to teacher's features, and offered to the learner as the audio corrective feedback. The visual feedback is also offered to enhance the modifications that occurred. Accent type pronunciation training experiments were conducted for 8 non-Japanese speakers, and the results showed that the training process could be facilitated by the feedbacks especially when they were asked to pronounce sentences.