Interspeech'2005 - Eurospeech
This paper discusses two well-known phonetic-phonological phenomena of Japanese, vowel devoicing and mora-timed rhythm. Regarding vowel devoicing as a process of vowels getting consonantal, it may change the mora-templated syllable structures of Japanese, resulting in the deviation from mora-timed rhythm. To investigate spontaneous Japanese with comparison to other languages, the label data of OGI_TS was analyzed. First, it seemed that vowel devoicing occurs more frequently in spontaneous Japanese than in controlled speech. In spontaneous speech, vowel devoicing frequently occurs even in the environments non-typical of vowel devoicing. Next, rhythm analysis showed that it is close to syllable-timed rhythm. These results suggest that vowel devoicing caused spontaneous Japanese deviates from mora-timed rhythm moving to syllable-timed.
Bibliographic reference. Komatsu, Masahiko / Aoyagi, Makiko (2005): "Vowel devoicing vs. mora-timed rhythm in spontaneous Japanese - inspection of phonetic labels of OGI_TS", In INTERSPEECH-2005, 2461-2464.