Abstract:
The aim of this research is to investigate and compare the behavior of the fundamental frequency of vowels of different phonation types and of vowels perturbed by different phonation types of initial and final consonants in Nyah Kur (Chaobon). The data was recorded from two groups of female speakers, aged 60-75 and 20-35, with five speakers in each group, and was acoustically analyzed with Praat 5.1.43. The effects of the phonation types of vowels and of initial consonants on the F0 values of vowels were statistically tested with t-Test (0.05 level of significance) and the effects of the phonation types of final consonants on the F0 values of preceding vowels were statistically tested with ANOVA (0.05 level of significance). The results are as follows: Phonation types of vowel: clear-voiced vowels have a higher F0 value than breathy-voiced vowels. The F0 difference is statistically significant from 0-100% of the normalized time in both speaker groups, thus supporting the hypothesis. The perturbation of initial consonants of different phonation types are: 1) vowels following voiceless initials have a higher F0 value than those following voiced initials and the F0 difference is statistically significant from 0-50% of the normalized time in both speaker groups, thus supporting the hypothesis; 2) vowels following voiceless sonorants have a higher F0 value than those following voiced sonorants, and the F0 difference is statistically significant from 0-50% of the normalized time in both speaker groups, thus supporting the hypothesis; and 3) for vowels following voiceless unaspirated and aspirated stops there are two findings, i.e. (i) vowels following voiceless unaspirated stops have a lower F0 value than those following voiceless aspirated stops, (ii) vowels following voiceless unaspirated stops have a lower F0 than those following aspirated ones, only at the beginning and then higher at the end of the vowel duration; the F0 differences as stated in (i) and (ii) are statistically significant from 0-50% of the normalized time in both speaker groups, thus failing to support the hypothesis The perturbation of final consonants with different phonation types are: 1) vowels preceding voiceless stops have a higher F0 value than those preceding voiceless fricatives and those preceding voiced nasals; 2) vowels preceding voiceless stops have a higher F0 value than those preceding voiceless fricatives and vowels preceding voiceless fricatives have a lower F0 value than those preceding voiced nasals; and 3) vowels preceding voiceless stops have a lower F0 value than those preceding voiceless fricatives and vowels preceding voiceless fricatives have a higher F0 value than those preceding voiced nasals. However, the findings do not confirm the hypothesis, i.e. the F0 difference is statistically significant from 50-100% of the normalized time in both speaker groups only in /u/. With regard to the pitch patterns of vowels of different phonation types and of vowels perturbed by the phonation types of initial and final consonants, they behave in the same way in both speaker groups. However, a clearer picture of pitch height and pitch contour behavior can be found in the older speaker groups speech, thus confirming the hypothesis. In conclusion, for Nyah Kur (Chaobon), clear-voiced vowels (V) have a higher pitch than breathy-voiced vowels (V̤). In the phonation types of consonants; aspiration (e.g. ph-) will be the cause of the highest pitch, voicelessness (e.g. p- hm-) will be the cause of higher pitch and being voiced (e.g. b- m-) will be the cause of the lowest pitch