Perception of Tone and Vo

The current study examines the interaction of syllable tones and vowel quantity in the production and perception of monosyllabic words of Thai. A speech corpus containing groups of words differing only as to tone type and vowel quantity was designed. These were embedded in a short carrier sentence of five mid tone syllables, with the target word being the center syllable. The utterances were analyzed with respect to the tonal and segmental features of the target words and F0 contours modeled using the Fujisaki model. Analysis shows that all mid tone sequences can be modeled using the phrase component only whereas the remaining tones require either single tone commands of positive or negative polarity, or a command pair. Based on the analysis results, a perception experiment was designed to explore the perceptual space between words of tone/vowel quantity contrasts. Results indicate, inter alia, that vowel quantity is perceived as shorter when words are presented in isolation than when embedded in a carrier sentence. Confusions generally occur more frequently between words of different vowel quantity than of different tones.