In this paper, we analyzed the durational differences between learners and native speakers in various speech units from the perspective of that the contrast between the stressed and the unstressed is one of the most important features to characterize stress-timing of English by comparison with mora-timing of Japanese. The results showed that the lengthening and shortening of learner speech were not enough to convey the difference between the stressed and the unstressed. Finally, it was confirmed that these durational differences strongly affected the subjective evaluation scores given by English language teachers.
Bibliographic reference. Nakamura, Shizuka / Kato, Hiroaki / Sagisaka, Yoshinori (2009): "Effects of mora-timing in English rhythm control by Japanese learners", In INTERSPEECH-2009, 1539-1542.