Naturalness on Japanese pronunciation before and after shadowing training and prosody modified stimuli

This study attempts to investigate the change of naturalness impression for the Japanese utterance by Japanese as foreign language learners (JFL) before and after pronunciation training (shadowing / repeating), and to discuss the crucial prosodic cue for the naturalness judgment. The speech of 8 JFL learners before and after pronunciation training was used, and their durational pattern, pitch pattern, or both of them were replaced with those of the model speech. 52 Japanese native speakers (JNS) assessed the naturalness of these stimuli. The results showed JNS judge the duration AND F0 modified stimuli most natural. In addition, the shadowing trained group tended to have been valued highly than the repeating trained group after the training. Furthermore, the acoustical analysis of speech material showed a difference of moraic structure and pitch accent between the shadowing and repeating group.