Kuo-You Huang
Psych. Dept., Natl. Chung-Cheng Univ., Chia-Yi, Taiwan
Chin-Hsing Tseng
Natl. Kaohsiung Normal Univ., Kaohsiung, Taiwan
Formant frequencies of vowels produced by male and female speakers of Mandarin and Taiwanese were measured. Twenty Mandarin-Taiwanese bilingual subjects produced three tokens of each vowel in the /lV/ (for Mandarin) and /kV/ (for Taiwanese) contexts. Like previous studies with other languages, women's formants were higher than men's in frequency, that high vowels had F1 values lower than low vowels, and that front vowels had F2 values higher than back vowels. Bark-difference measures were obtained from the Bark-transformed formant frequencies; that is F0 was subtracted from F1, F1 from F2, F2 from F3, F2 from F4, and F3 from F4. Two Bark-difference measures (i.e., F1-F0, F3-F2) correspond well to vowel height and point of articulation, respectively. Most importantly, high vowels have F1-F0 values within 3.5 Bark and front vowels have F3-F2 differences also within 3.5 Bark. These transformations largely reduced the between-speaker variability related to the gender factor. Results of these Mandarin and Taiwanese vowel data agree with English data [A. K. Syrdal and H. S. Gopal, J. Acoust. Soc. Am. 79, 1086--1100 (1986)] and support the universality of the category-independent auditory theory of normalization.