Acoustic-phonetic characteristics of Thai filled pauses in monologues

Filled pause (FP) is one type of disfluent phenomena that is commonly found in everyday speech. It has been widely studied in many languages, but little is known about this topic in Thai. This work explored three important acoustic-phonetic characteristics of Thai filled pauses in monologues. To elicit target monosyllabic tokens of FPs and those of regular word (RW) counterparts, 31 Thai adult females were asked to watch two short cooking videos and describe the contents. They were also asked to read out loud target word lists. Three acoustic measures: syllable duration, first (F1) and second formant (F2) frequencies were taken from 738 tokens. Across vowel contexts, only F2, not F1, in FPs, was significantly different from that in RWs. Differences in syllable duration between RWs versus FPs were near significant. The findings suggest that Thai speakers produced FPs in a presumably different way from RWs. In FPs, the syllable was relatively lengthened and the tongue position was moved towards the center of vowel space. Future directions include a detailed analysis of FPs in terms of amplitude, fundamental frequency, pause duration before/after fillers and other nonlinguistic factors.