美坝白语声调的发声变异初探

A Preliminary Study of Variations of Phonation Features in Meiba Bai

大理喜洲美坝村白语属于白语东部方言。本文从发声角度研究了美坝白语的声调，提取了四个发音人（两男两女）的基频、开商和速度商参数。基频参数反映声带振动的快慢，开商和速度商体现声带开闭的状态。本文用半音法来转换基频参数，发现紧调和松调的音调变化幅度有较大差异，紧调中的高音和低音最多相差达11个半音，而松调中的高音和低音最多只相差7个半音。可见，紧调可以扩展调域。从声调和综合发声参数的表现来看，美坝白语声调系统的发声基础正处在变异之中，不同的松紧调对立组的变异速度不一样，不同的人采用不同的策略来区分声调，年龄大的多以不同发声类型（开商和速度商）来区分声调，而年龄小的则倾向于用基频来区分声调；女性比男性更多地保持了用不同发声类型来区分声调的策略。就特殊发声类型的性质而言，只有男2的紧调T7使用的是典型的糙音（harshvoice），女2的紧调T2使用的是典型的高音调嗓音（high-pitched），其他的特殊发声类型都不典型。

The language spoken in Meiba village, Xizhou town, Yunnan province belongs to the eastern branch of the Bai language. In this paper, based on EGG signals of four speakers, including two males and two females, three parameters, namely Fundamental Frequency （ F0 ） , Open Quotient （OQ） and Speed Quotient （SQ） , are observed to examine acoustic characteristics of tones. F0 represents the speed of vibration of vocal cord, and the open-close state of vocal cord can be examined by observing OQ and SQ. Fo data are converted using the chromatic scale, and a significant difference in tonal range is found between lax and tense tones. The highest tone in the tense tones is eleven semitones higher than the lowest tone, while among the lax tones there is only a seven-semitone difference between the highest and the lowest tones. This suggests tense tones may have a wider tonal range. Furthermore, it is found that the cues people rely on to differentiate Meiba tones are changing. Specifically, different tense-lax tone pairs are changing in different speed, and the changes vary with different social groups. Older speakers tend to distinguish different tones by phona- tion types （ OQ and SQ ） , while young speakers prefer using pitch to differentiate tones. Female speakers are more inclined to distinguishing tones through phonation features. As for the nature of the phonation types, T7, a tense tone, is produced by male speaker No.2 as a typical harsh voice; T2, a tense tone, is produced by female speaker No.2 as a typical high-pitched voice. Phonation types involved in the other tense tones are complex and yet to be defined in future research.