ABSTRACT
OBJECTIVE: The study is going to investigate the fundamental frequency (F(0)) and perturbation measures of sustained vowels in 360 native Malaysian Malay children aged between 7 and 12 years using acoustical analysis. METHODS: Praat software (Boersma and Weenink, University of Amsterdam, The Netherlands) was used to analyze the F(0) and perturbation measures of the sustained vowels. Statistical analyses were conducted to determine the significant differences in F(0) and perturbation measures across the vowels, sex, and age groups. RESULTS: The mean F(0) of Malaysian Malay male and female children were reported at 240±34.88 and 254.48±23.35Hz, respectively. The jitter (Jitt), relative average perturbation (RAP), five-point period perturbation quotient (PPQ5), shimmer (Shim), and 11-point amplitude perturbation quotient (APQ11) of Malaysian male children were reported at 0.43±0.26%, 0.25±0.16%, 0.26±0.15%, 2.48±1.61%, and 1.75±1.04%, respectively. As for female children, the Jitt, RAP, PPQ5, Shim, and APQ11 were reported at 0.42±0.22%, 0.25±0.14%, 0.25±0.13%, 2.47±1.53%, and 1.75±1.10%, respectively. CONCLUSIONS: No significant differences in F(0) were reported across the Malay vowels for both males and females. Malay females had significantly higher F(0) than that in Malay males at the age of 8, 10, and 12 years. Malaysian Malay children underwent the nonsystematic decrement in F(0) across the age groups. Significant differences in F(0) were found across the age groups. Significant differences in perturbation measures were observed across the vowels in certain age groups of Malay males and females. Generally, no significant differences in perturbation measures between the sex were observed in all the age groups and vowels. No significant differences in all the perturbation measures across the age groups were reported in both Malaysian Malay male and female children.
