Acoustic Phonetic Study on the Tones of Three-word-sentence in Lao

MASUKO Yukie / SUZUKI Reiko

This study examines the acoustic phonetic characteristics of Lao tones observed in sentences consisting of three monosyllabic words in order to compare with those in Lao monosyllabic and disyllabic words which we examined in 2017.

We focus on the tonal patterns of the second words in a sentence. All possible combinations of Lao five tones assigned to each word, 125 patterns in total, were recorded. We measured F0 of three points in each pitch curve; the beginning, middle, and final points for level tones, and the beginning, either peak or bottom, and final points for falling or rising contour tones.

WThe pitch curves of these patterns shows that tonal phonemic contrasts are shown by two marked characteristics, one is to reach the ‘bottom pitch’, the other, to reach ‘high’ of the speaker’s voice. What is the most characteristic of Lao tonal phonemic opposition is that nakedness of each tone may be represented not only by one, but also by two pitch patterns.

Tone 4 marked with ‘bottom pitch’ opposes Tone 5 unmarked in that regard. Tone 2 marked with ‘bottom pitch opposes Tone 3 in that regard, but at the same time, Tone 3 marked with ‘high’ opposes Tone 2, unmarked in that regard. As a result, Tone 2 and Tone 3, the former marked in one feature is unmarked in the other one, and vise versa. Tone 1, which is unmarked in that it does not reach ‘bottom pitch’ nor ‘high’, oppose Tone 2 and Tone 3. The same two unmarkedness of Tone 1 then works as markedness in its contrast with Tone 4, unmarked not ‘high’.

Thus, hierarchic contrast in markedness and unmarkedness can explain phonemic contrast in Lao five tones.