基于言语数据库的汉语音高下倾现象研究

提出了一种通过语句中声调音域低音点和次低音点求出语调短语低音线的方法,并以低音线为基准,考察从大规模言语语料库中随机抽取的汉语自然语句的语调特征。研究结果表明,与已有的汉语句末语调理论不同,汉语同样具有各种语言中普遍存在的音高下倾和重置的语调特征。低音线的下倾和重置可以出现在音步、语调短语和语句等不同的韵律单元中,表现最明显的是在语调短语这一级。实验结果支持汉语语调双线模型中高音线和低音线语言学功能不同的观点。     

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。     

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。      

汉语韵律层级结构边界的声学分析

基于大规模语料库,对比了较慢和较快两种语速的语料,研究了韵律层级结构边界的声学表现。研究主要得到以下结果: (1)汉语语句音高的下倾和重置是由音域下限的移动实现的。 (2)韵律词边界的声学线索是低音线的不连续性和边界前音节的延长, 一般没有无声段。 (3)韵律短语和语调短语边界的声学线索是低音线重置和无声段。并且,边界等级越高,低音线重置程度越大,无声段的长度也越长。 (4)知觉等级与无声段长度成对数增长关系。     

韵律短语边界对降阶和焦点后音高骤降的影响

通过设计特定声调组合和语境的实验室语句,考察了韵律短语边界对语句中降阶和焦点后音高骤降的影响规律,以及降阶和焦点的作用域。结果发现,在由两个韵律短语组成的语句中,韵律短语边界会阻断前一短语中的降阶作用,降阶的作用域是韵律短语。焦点的实现与降阶不同:焦点后的正向音高降低作用会跨越韵律短语边界,使得后一韵律短语的高音线明显降低;如果后一韵律短语中有降阶,则焦点的跨边界音高降低作用会与降阶作用累积在一起,产生更低的高音线,说明焦点的作用域是语调短语。但当后一韵律短语也出现焦点时,音高重置阻断了前一短语中焦点的正向音高降低作用,此时两个焦点分别独立地实现。      

汉语口语与朗读话语陈述句音高比较

汉语语句通常存在音高下倾现象,然而关于语句内部韵律词的具体音高表现目前的研究尚较欠缺。本研究使用的对话语料选自973电话语料库,包括69段对话,涉及79位说话人;朗读话语语料为广播电台两位主持人的新闻播音,长度为221个语句,对语句内部韵律词的高音点、低音点及音域进行了分析,结果显示对话与朗读话语多数语句的音高呈前高后低的走势,不过口语对话较长语句前半段的音高下降趋势不太明显。与朗读话语相比,口语对话韵律词的音域通常比较小。对话语句最后一个韵律词的音域相对较大,而朗读话语内部韵律词的音域大多没有差异。本研究的结果,将有助于语音合成中语句内部韵律词音阶及音域的构拟。      

音高和时长在语篇语句重音中的作用

本研究通过30篇自然叙事语篇,以韵律词为分析单位,对语篇中音高和时长在语句重音中的作用进行探讨,结果主要发现:(1)韵律词音域的相对宽窄对语句重音起着最主要的作用.(2)音高和时长在语句重音中的作用受到小句音域宽度和韵律词等级的交互影响.在正常韵律诃中,1级重音由音高和时长共同发挥作用来实现;2级重音主要靠音高起作用.在强化韵律词中,小句音域越窄,时长在语句重音中的作用越重要.(3)音高和时长之间的相关性主要受到韵律词强度的影响,在弱化、正常和强化韵律词中,音高和时长分别表现出普遍的正相关、不相关和负相关.     

汉语语调降阶的实验研究

采用设计特定声调组合的实验室语句的方法,研究了汉语普通话语调降阶的规律。结果发现,在普通话语调中,同样存在自动降阶和非自动降阶两种音高现象。在有低音介入的非自动降阶中,低音对后音节音域的影响表现在使音域上限降低,音域的下限保持不变;因此汉语中的降阶是语调高音特征的表现;低音特征声调会使低音后的高音发生正向降低和低音前高音的逆向提高,并且这两种作用是可以相互包容的。在自动降阶中,高音线的下降趋势是线性的,它受重音位置及重读程度的影响,在发音人中有较大差异。与已有的其他语言降阶研究的结果相比,汉语的降阶率不是固定的,且降阶的作用范围并不只局限于同低音相邻的音节。     

普通话与台湾国语声调的对比分析

本文对普通话和台湾国语的单字调和语句中声调的音高、音长进行了研究．结果表明,由于受到闽南话的影响台湾国语阴平和阳平在音高表现上和相应的普通话音节有所不同;普通话上声是“曲折调”,其后半段的调型特征为“微升”,台湾国语上声是“低降调”;单念时普通话声调的时长为,上>阳>阴>去,台湾国语则为,阴>阳>上>去。二者在语句中声调的差异主要表现为:普通话阳平是“中升调”,而台湾国语阳平是“中平调”;韵律短语边界效应在台湾国语中的作用力更大;受边界效应影响时,普通话各声调音节的时长延长基本上是相同的,而台湾国语中阴平和阳平延长的程度显著大于上声和去声;时长统计结果表明,语句中普通话上声长于去声,短于阴平和阳平,而台湾国语上声则是四个声调中最短的。     

边界强度对焦点实现方式的影响

汉语普通话中,单焦点主要表现为焦点词音高上升和焦点后音高压缩(Post-Focus-Compression,PFC),而双焦点句中第一个焦点后音高压缩有限。韵律边界强度是否影响焦点的实现方式,特别是焦点后音高压缩?本实验借助句法上词、短语、分句和句子的分类,在句中关键词(X)后设定了4种韵律边界强度。通过问句引导的4种焦点条件分别为:关键词X为焦点,句末词Y为焦点,词X和Y都是焦点(双焦点),以及中性焦点。语音分析结果显示:(1)焦点词都表现出音高上升和时长延长,增加量在单焦点和双焦点间没有显著差异,且不受焦点词后边界强度的影响;(2)双焦点句中第一个焦点后的音高压缩会被中等强度的边界减弱,而只有非常强的边界才会减弱单焦后的音高压缩;(3)随韵律边界强度增加,边界前的词时长增加,但延长量是有上限的,且不受焦点位置的影响。总体来说,韵律边界和焦点在语调上是平行编码的。      

Experimental study on declination in Chinese intonation

The aim of designing sentences with special tone combinations is to investigate the declination tendency of intonation in Chinese Putonghua.The result shows that baselines of prosodic phrases(PP),as the basic declination units,show the phenomena of declination clearly,and the declination slope is in inverse proportion to the length of PP.Different tone combinations of PP have different declination slopes.The primary conclusions are as follows: (1) If low points are at the beginning of prosodic word(PW),the absolute value of baseline slope is larger than those at the end;(2) The declination of PP is larger,if it is at the beginning of sentences than that at the end;(3) When there are several PPs in sentences,although in different syntactic relations the degree of declination is different,they have the common ground of PP declination.     

The effects of prosodic phrase boundary on the pitch lowering of downstep and focus

The effects of prosodic phrase(PP)boundary on the pitch lowering of downstep and focus,as well as the domains of them were investigated in Chinese Putonghua,by using designed sentences which consist of two prosodic phrases(i.e.,PP1,PP2).The results showed that:(1)The PP boundary blocked the downstep effect in the preceding phrase,indicating that PP is the domain of downstep.(2)The post-focus F_0 lowering effect in PP1 spread across the PP boundary and lower the FO contour of PP2.If there is a downstep effect in PP2,the postboundary compression effect of the prior focus will accumulate with the downstep,producing further lowered contour.Therefore,the domain of focus is an intonational phrase(IP).(3)When there is one contrastive focus in each phrase,the outstanding pitch reset elicited by the second focus will block the FO lowering effect of PP1 onto PP2,and the two foci are realized independently.     

Crystallization Kinetics of Linear and Long‐Chain Branched Polypropylene

Isothermal crystallization kinetics of linear polypropylene (PP) and long‐chain branched (LCB) PPs were investigated on the basis of the Avrami theory. The Avrami exponents of LCB PPs are smaller than that of linear PP; moreover, they decrease with an increasing LCB level. The crystallization half‐time of LCB PP depends more strongly on the crystallization temperature than does that of linear PP. The Lauritzen‐Hoffman theory was used to study the effect of LCB on the crystal growth rate of PP. The fold surface free energy of LCB PP is lower than that of linear PP; moreover, it decreases with an increasing LCB level. However, when the LCB level is over a certain value, the fold surface free energy increases again. Furthermore, the crystal structures of linear PP and LCB PPs were studied by wide‐angle X‐ray diffraction (WAXD); it was observed that linear PP can crystallize in the α and β forms, while LCB PPs have only the α crystalline form. Moreover, the relative intensities of different α peaks were also influenced by the LCB level.     

焦点、词重音与边界调对语调短语末词基频模式的影响

研究了语调短语边界处焦点、词重音位置与上升的边界调对语调短语末词基频模式的影响。通过分析两个美式英语语料库语调短语末词的声学特征,我们发现当该单词是焦点时,重音的基频峰值比边界调的尾值高;边界调在重音实现后才充分体现出来;词重音在音节结构中后移会压缩词重音后基频调域范围。当语调短语末词不是焦点时,边界调的上升趋势从开始就体现出来,并压制了词重音的基频凸显。我们的结论是,焦点可以通过提升词重音基频峰值的高度完成;焦点和边界调实现的力度受词重音所处位置限制,在极端的情况下,边界调只能在语调短语最末音节的尾部实施。在有限音段上这些韵律特征都有表达其功能最彻底的一段位置,它们竞相展现,此消彼长。      

The perception of fundamental frequency declination

A series of experiments was carried out to investigate how fundamental frequency declination is perceived by speakers of English. Using linear predictor coded speech, nonsense sentences were constructed in which fundamental frequency on the last stressed syllable had been systematically varied. Listeners were asked to judge which stressed syllable was higher in pitch. Their judgments were found to reflect normalization for expected declination; in general, when two stressed syllables sounded equal in pitch, the second was actually lower. The pattern of normalization reflected certain major features of production patterns: A greater correction for declination was made for wide pitch range stimuli than for narrow pitch range stimuli. The slope of expected declination was less for longer stimuli than for shorter ones. Lastly, amplitude was found to have a significant effect on judgments, suggesting that the amplitude downdrift which normally accompanies fundamental frequency declination may have an important role in the perception of phrasing.     

Contrastive analysis on tone between Putonghua and Taiwan Mandarin

The differences of the pitch and duration of Chinese syllables between Putonghua （PTH） and Taiwan Mandarin （TM） were studied. The speech materials to be used are not only isolated syllables, but also sentences. The results reveal that： For the isolated syllables, T1 and T2 in TM are influenced by Minnan dialect, therefore their pitch are lower than those in PTH. T3 is fall-rise in PTH, while it is fall in TM. Moreover, the syllable duration sequence for different tone is T3〉T2〉T1〉T4 in PTH, while it is T1〉T2〉T3〉T4 in TM. For the syllables in sentences, T2 is mid-rise in PTH, while it is mid-level in TM. And the T3 is longer than T4 but shorter than T1 or T2 in PTH, while it is the shortest in TM. Furthermore the effects of prosodic phrase boundary on duration for different tones are almost the same in PTH, but the lengthening part of T1 or T2 is longer than that of T3 or T4 in TM.