Speech Prosody 2004
This study explores the effect of accent on duration from the viewpoint of Japanese rhythmic structure. Phonetic experiments reveal that prepausal vowel duration significantly and consistently varies by more than 40% depending on accent and position. This great degree of durational variation restricted to prepausal position suggests that the prepausal position is free from the constraints of mora timing in Japanese.
Bibliographic reference. Mori, Yôko (2004): "Elasticity of prepausal vowels in Japanese rhythmic structure", In SP-2004, 243-246.