Consonantal and Prosodic Influences on Korean Vowel Duration

In this paper, we describe some consonantal and prosodic influences on vowel duration in Korean. In particular, the effect of different obstruents on the duration of following vowels was examined. With a large set of artificial utterances recorded by a single speaker, we studied four factors on vowel duration: the pre-vocalic context, the post-vocalic context, clause-final lengthening and phrase-internal shortening. The results show that tense aspirated obstruents shorten the following vowels most, followed by lax obstruents and tense unaspirated obstruents. The influence of obstruents on preceding vowels is negligible. Phrase-initial vowels are longer than any other phrase-internal ones, while clause-final vowels are longest. We have applied these findings in a Korean speech synthesis system being developed at UCL.