Theraphan L-Thongkum, Chommanad Intajamornrak, Kanitha Phutthasatien, Yupaporn Huadsiri, Supaporn Phalipat
A Synopsis of Mal Phonetics
The result of our literature survey shows that an acoustic study of Mal, a Khmuic language, does not exist. Funded by the Thailand Research Fund (2004-2007), acoustic studies of Mal were made by the CU research team. The speech of three female speakers was recorded, measured and analysed by computer programmes and tested by t-Test (p < 0.05). With regard to the acoustic characteristics of consonants, vowels and tones, the following are our findings.
The three types of initial stops, i.e. bilabial, alveolar and velar, can be identified using the Locus Equation (LE) method. The distinct slopes and y-intercepts of the linear equation can characterize the place of articulation. However, using the slope value seems to be more effective in identifying the place of articulation than the y-intercept value. Velar stops have the highest slope, while the lowest slope occurs in alveolar stops
The distinction between the average duration of short and long vowels is statistically significant. The ratio of duration for long-to-short vowels is 2:1. First formant (F1) is the cue to distinguish short and long vowels, while second formant (F2) can be used as the cue for the back vowel. The vowel space of short vowels is smaller than that of their long counterparts but the variation within the space of each short vowel is more dispersed. The variation of each vowel in the vowel space does not depend on vowel inventory size.
Vowels following voiceless initial stops and sonorants have a higher fundamental frequency (F0) value than those following the voiced ones and the F0 difference is statistically significant. In brief, the phonation type of initial stop and sonorant has an influence on the F0 value of the following vowel.
Some Mal varieties have become tonal languages with two tones, i.e. /high/ vs. /low/. Contact with the northern Thai dialect (Kham Mueang) seems to have been the cause of tonal birth in Mal not internal factors (e.g. sound change, etc.).