Phonetic realization and perception of prominence among lexical tones in Mandarin Chinese.

摘要

Linguistic prominence is defined as words or syllables perceived auditorily as standing out from their environment. It is explored through changes in pitch, duration and loudness. In this study, phonetic realization and perception of prominence among lexical tones in Mandarin Chinese was investigated in two experiments. Experiment 1 explored phonetic realization of prominence. The primary aim of this experiment was to compare and contrast acoustic characteristics of a target word produced under four conditions: (a) unaccented and unfocused; (b) accented but unfocused; (c) unaccented but focused; (d) accented and focused, among four tones. Ten native speakers of Chinese were recorded reading materials in a natural fashion with the target word appeared in the above four positions. The recorded data were segmented and acoustically measured for acoustic parameters: vowel duration; mean and maximum of intensity; mean, maximum, minimum and slope of F0. The results showed that vowel duration lengthening was the main acoustic parameter associated with accent while an increase in vowel duration, mean and maximum of intensity and F0, and slope of F0 was associated with focus realization. It was also found that acoustic parameters used to realize focus were varied from tone to tone: an increase in duration, F0, and intensity was presented in focus realization for Tone 1 (high level tone) and Tone 4 (high falling tone); duration and F0 were used to implement focus for Tone 2 (mid-high rising tone); while duration and intensity were used in Tone 3 (low falling-rising tone). Acoustic cues used to perceive prominence were investigated in Experiment 2. In this experiment, acoustic parameters found to have been used to realize focus in Experiment 1 were compared in pairs to test native speakers' preference in focus perception. Twenty native speakers of Chinese participated in the 'preference' judgment. The results showed that duration, mean and maximum of intensity cues were selected more often than pitch cues in focus perception. These results suggested that phonetic realization of prominence in Mandarin Chinese was affected by category of prominence (i.e., focus or accent) and tonal contexts. Moreover, acoustic parameters used by native Mandarin Chinese to produce focus were different from those used in their perception of focus.