丽江彝族中小学教师普通话单字调声学实现特征研究

A Study on the Acoustic Realization Characteristics of Mandarin Monosyllabic Tones by Yi Ethnic Primary and Secondary School Teachers in Lijiang

摘要: 本文以20名丽江彝族中小学教师为研究对象，采用实验语音学方法考察其普通话单字调的语音特点。实验材料包括32个普通话常用单音字，阴平、阳平、上声、去声各8个。利用Praat进行语音切分和基频提取，将每个目标音节按相对时长等距提取10个采样点，并通过发音人内部归一化将原始基频转换为T值。结果表明：教师组普通话四个单字调呈现出相对清楚的基本音高轮廓，但不同调类的内部实现仍存在差异。其中，阴平虽能保持平调轮廓，但整体调层偏低；阳平虽有后段上升趋势，但前段下探较深，起调位置偏低；上声能够形成降–升曲折轮廓，但低谷后的回升幅度不足；去声高降方向较为清楚，是四个声调中实现相对充分的调类。同时问卷结果显示，教师自评的声调困难也主要集中于第二声和第三声。结合已有彝语声调研究，阳平和上声的实现特点可能与既有声调经验有关。因此研究认为，该群体普通话单字调的差异主要体现在声调内部的音高运动过程，而非四声基本调型的缺失。

Abstract: This study investigates the phonetic characteristics of Mandarin monosyllabic tones produced by 20 Yi ethnic primary and secondary school teachers in Lijiang using an experimental phonetic approach. The experimental materials consisted of 32 commonly used Chinese monosyllabic characters, with eight items representing each of the four tones: Yinping, Yangping, Shangsheng, and Qusheng. Praat was used for speech segmentation and fundamental frequency (F0) extraction. Ten equidistant sampling points were extracted from each target syllable according to its relative duration, and the raw F0 values were converted into T values through within-speaker normalization. The results indicate that the participants have established the basic categories of the four Mandarin tones, although the phonetic realization of some tones still differs from typical Mandarin tonal patterns. Specifically, Yinping maintains a level contour but is realized at a relatively low pitch register; Yangping exhibits a rising tendency in its latter portion but shows a pronounced initial dip and a relatively low onset; Shangsheng displays a falling-rising contour, but the rise following the low point is insufficient; and Qusheng exhibits a clear high-falling contour and is relatively well realized among the four tones. The questionnaire results further show that the teachers’ self-reported difficulties are mainly concentrated in the second and third tones. In light of previous research on Yi ethnic tone systems, the realization characteristics of Yangping and Shangsheng may be related to pre-existing tonal experience. Overall, the findings suggest that the differences in these teachers’ Mandarin monosyllabic tones primarily concern tone-internal pitch movements rather than the absence of basic tonal contours.