不同语调条件下的声调音高实现

从调类个性、句中位置和重音级别3个层面的语音分析,考察普通话4个声调在不同语调条件下的音高实现。目标词被置于3种不同的焦点位置(即句重音最强的位置)和两种不同的非焦点位置(即非句重音位置)上,对目标词的调域以及目标声调的高音点和低音点进行了观察分析。实验结果表明,(1)在焦点条件以及非焦点条件下,阳平的音高位于调域的中低音区,去声低音点的理论调值尽管低于阳平低音点,但去声低音点在音高实现上往往接近阳平低音点甚至会高于阳平低音点;(2)焦点在句首位置表现为调域向上下两个方向扩展,在句末位置则表现为调域整体上抬,但不同声调的高音点并不都与调域上限同比例变化,不同声调低音点的变化也并不都与调域下限同比例变化;(3)重音后音节的音高对焦点音节的依赖关系受音步组合关系的制约,焦点和焦点后音节若在同一音步内,焦点后音节的音高与焦点音节的音高关系类似轻声音节与其前接非轻声音节的音高关系,焦点和焦点后音节之间如果存在音步边界,焦点后音节的音高表现出一定的独立性。这些结果说明了语句中声调音高实现的复杂性,一个具有较好预测性的汉语普通话语调模型的建立需要包括焦点结构、韵律结构、协同发音、调类个性等不同层面信息的诸多细节化规则。

The effect of intonation on pitch realization of the tones in Chinese Putonghua

Pitch realization of the four tones in Chinese Putonghua is investigated acoustically on the levels of tone category, location in sentence and accent pattern. In the experiment, the target words containing target tones were embedded in three kinds of sentence focus and two kinds of non-focus positions in the material, and the whole pitch ranges of the words and the high/low points of the target tones were analyzed. The results revealed the complexity of tonal variation under intonational effect. First, Tone 2 was located in the lower register of the tonal range under both focused condition and neutral unfocused condition, and the low point of Tone 4 was close to that of Tone 2 and sometimes higher although the theoretical tonal value of the former was lower than that of later. Secondly, under sentence-initial focus condition, tonal range expanded upward and downward, while under sentence-final condition, the whole tonal range was raised. In addition, the high points of the four tones did not necessarily vary in proportion to the top threshold of the pitch range, and so did the low points of the tones to the bottom threshold. Thirdly, the pitch of a post-focus tone was constrained by its rhythmic relation with the focused tone. When located in a same rhythmic foot, the pitch of the post-focus tone depended on the pitch of the focused tone, and the relationship between the two tones was similar to that between a normally stressed tone and its following neutral tone. Yet, when there was a foot boundary between the focused tone and its following tone, the post-focus tone tended to keep its tonal feature to some extent. These results imply that lots of detailed rules that take focus structure, rhythmic structure, tonal coarticulation and tonal feature into consideration are needed to establish a well-predictive intonation model in Chinese Putonghua.