This article deals with the application of experimental (acoustic and perceptual) phonetics to the teaching of pronunciation. The issue is illustrated by Japanese speakers' difficulties in learning French vowels in general. Experiments were specifically conducted on the vowels /u y ø/. The objective is to elucidate the case of individual phones depending on whether or not their phonemic status and their phonetic realization differ in the two languages under study. The French /u/ differs phonetically from its phonemic counterpart, the Japanese /u/. The present study confirms that the French /u/, which is phonemically identical (to the Japanese /u/), turns out to be more difficult than the "new" vowel /y/, which has no phonemic or phonetic counterpart in Japanese. The production of /ø/, which is phonemically "new" but acoustically close to the Japanese /u/, seems to present still less difficulty. The study also brings a reflection on the teaching of pronunciation. The analysis of general French textbooks published in Japan suggests that learners and teachers are seldom aware of the difference in the difficulties caused by the three vowels /u y ø/. Also, some methods of pronunciation teaching (some traditional, others new) are presented in terms of how they foster learners' awareness of these difficulties. The goal of this study is to help shed light on the learning processes of the pronunciation of foreign languages, and to improve its learning and teaching.
