The evaluation of Chinese aspiration sounds uttered by Japanese students using VOT and power

A Chinese aspiration is generally considered to be very difficult to be reproduced by Japanese students. The difficulty is caused by lack of aspiration in Japanese pronunciation. Voice onset time (VOT) is one of the important measures to evaluate the quality of pronunciation. In this paper, VOT for Chinese aspiration sounds pa[p´a], pi[p´i], po[p´o] and pu[p´u] were measured, as they were pronounced by 40 Japanese students, who have been studying Chinese 3 hours per week for one year. The uttered sounds were also evaluated by native Chinese speakers. The paper demonstrates that good pronunciation has generally long VOT. However, some exceptions were observed. Furthermore analysis of temporal variations of breathing power during the VOT period demonstrates that the power is low in the lower grade sound. The paper shows that the VOT is only one measure of clear pronunciation of the Chinese aspirations. Other measures, such as the power and the energy, have been introduced and their importance as a means to evaluate the quality of pronunciation have been confirmed.