Abstract
Effects of consonantal environment and speech rate on vowel devoicing are examined from glottal opening patterns of an Osaka subject. Results demonstrated that for the initial consonant of /CVC/, the glottis widely opened both for stops and fricatives, which presumably facilitates devoicing. For the second consonant, the glottis widely opened for fricatives but not for stops. However, vocal fold vibration of the preceding vowel continued into the consonants only for fricatives. Thus, fricatives are likely to suppress devoicing in intervocalic position. For the consonant /h/, continuation of vocal fold vibration lasts until the end of the consonant, which will strongly suppress devoicing. A sequence of fricatives suppresses devoicing presumably due to faster glottal adduction for fricatives than stops. The distance of glottal openings between preceding and following consonants becomes shorter in fast speech, which may facilitate devoicing.
