15th International Congress of Phonetic Sciences (ICPhS-15)

Barcelona, Spain
August 3-9, 2003


Vowel Duration and its Effect on the Frequency of Vowel Devoicing in Japanese: A Comparison Between Tokyo- and Osaka Dialect Speakers

Masako Fujimoto (1), Shigeru Kiritani (2)

(1) National Institute for Japanese Language, Japan
(2) Kobe Kaisei College, Japan

"Vowel devoicing" is a widely observed phenomenon in Japanese. It occurs more frequently in the Tokyo dialect (standard Japanese) and less frequently in the Osaka dialect. Previous studies have suggested that the frequency of devoicing is highly related to the speaking habits of the speakers and how carefully they pronounce their words. It has been said the speakers of the Tokyo dialects pronounce vowels less carefully than the speakers of the Osaka dialects. The present study examines the relation between vowel duration and the occurrence of vowel devoicing.
   The results showed the relative duration of the vowel in a mora in a non-devoicing environment was significantly shorter for Tokyo speakers, who consistently showed vowel devoicing, than for the Osaka speakers who did not show vowel devoicing. However, the vowel duration of the Osaka speakers who showed devoicing in fast speech is not necessarily longer than that of Tokyo speakers. Furthermore, the duration of /i/ of Tokyo speakers was constantly short regardless of speech rate, while that of /e/ varies corresponding to speech rate. This finding indicates that Tokyo speakers categorically differentiate the pronunciation of high- and non-high vowels. Phonetic and phonological aspects of vowel devoicing are discussed based upon the present results and those of our physiological study.

Full Paper

Bibliographic reference.  Fujimoto, Masako / Kiritani, Shigeru (2003): "Vowel duration and its effect on the frequency of vowel devoicing in Japanese: a comparison between Tokyo- and Osaka dialect speakers", In ICPhS-15, 3189-3192.