Acoustic Analysis of Thai Tones in Thai Trisyllablic words

MASUKO Yukie

This study examines the acoustic phonetic characteristics of Thai tones observed in trisyllabic words in order to compare with those in sentences made of three monosyllabic words which we have already examined.

Since patterns of combination of Thai five tones in trisyllabic words may differ from those in in sentences with monosyllabic words, we analyzed duration and pitch curve of the former.

We found that the last syllable has a very long duration. In case the last syllable is a checked one with phonemically short vowel, however, it has relatively short duration, although it is still longer than that in the first or the second syllable.

Duration of the first or the second syllable with a phonemically long vowel tends to be longer. Even that with a phonemically short vowel may be pronounced long, due to the internal structure of the word. In contrast, duration of phonemically long vowels is always pronounced long. It needs further examination how and to what extent the internal word structure is relevant to duration of syllables.

We found that shapes of pitch curve depend on the duration of syllables, and that they are quite similar to those of three word sentences. Since the number of patterns and words which we have analyzed is limited, patterns of tones in light syllable need further examination.