The effect of stress on vowel space in daxi hakka Chinese

The present study examined the effect of stress on vowels, specifically duration, formant frequency and acoustic vowel space in CV syllable in Daxi Hakka Chinese. F1 and F2 values were measured at three equidistant time locations. Results show that the absence of stress results in the reduction of vowel duration, which is shortened by 23% in the unstressed condition. The presence of stress affects formants by raising F2 for front vowels, raising F1 for low vowels, and lowering F2 for back vowels. Space areas in the stressed condition are significantly greater than their unstressed counterparts in all three measurement points. The mean space areas are compressed by 17% from the stressed to the unstressed condition. The mean space areas in 50% point are the largest in the two stress conditions. There is a positive correlation between interspeaker duration and vowel space areas.