The Effects of Speaking Rate on Mandarin Tones

Abstract

This study examined the acoustic changes of speaking rate on Mandarin tones. 8 native Mandarin speakers produced 17 Chinese words with four tones at slow, normal and fast speaking rate. Acoustic parameters, such as consonant and vowel duration, F0 at onset and offset of vowels and the first, second and third formant frequencies were examined. The ΔF0 and the Turning Point of Tones 2 and 3 were also examined. Results showed significant changes in duration in both consonant and vowels as a function of speaking rate. The findings showed that the vowel duration of a shorter tone, such as tone 4 increases relatively more than a longer tone, such as tone 3 at a slower speaking rate. Results also found that the values of F0 at vowel onset and offset varied as a function of speaking rate. Formant frequency values showed little change when all the stimuli were examined. When the front and back vowels were analyzed separately, F2 values did show significant variations when speaking rate changed. F2 values of front vowels decreased and F2 values of back vowels increased, with an increase in speaking rate. In terms of ΔF0 and TP of Tones 2 and 3, the results showed changes across speaking rate, with a decrease in ΔF0 and an earlier TP as speaking rate increases. These effects were most prominent for Tone 3. These findings are interpreted in terms of how tones are implemented under different speaking rates in production.