Quantitative characterizations of speech rhythm: syllable-timing in Singapore English

British English and Singapore English are said to differ in rhythmic patterning. British English is commonly described as stress-timed, but Singapore English is claimed to be syllable-timed. In the present paper, we explore the acoustic nature of the suggested cross-varietal difference. In directly comparable samples from British English and Singapore English, two types of acoustic measurements were taken; we calculated a variability index reflecting changes in vowel length over utterances, and measurements reflecting vowel quality. Our findings provide acoustic data which support the hypothesized cross-varietal difference in rhythmic patterning; we show (1) that successive vowel durations are more nearly equal in Singapore English than in British English, and (2) that reduced vowels pattern more peripherally in the F1/F2 formant space in Singapore English than in British English. We complete the paper with a comparison of our vowel variability index with a set of acoustic measures for rhythm proposed by Ramus, Nespor, and Mehler (1999), which focus on variability in vocalic and intervocalic intervals. We conclude that our variability index is more successful in capturing rhythmic differences than Ramus et al. (1999)'s measures, and that an application of our index to Ramus et al.'s intervocalic measure may provide a further diagnostic of rhythmic class.