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.     

汉语语句重音对音高和音长的影响

提高汉语合成语音的自然度的关键是要建立一个完善的汉语韵律模型．本文以连续的广播语言为研究对象,对汉语中语句重音对韵律特征参数的影响进行了初步探讨,分析了不同语句重音条件下音长和音高的变化及其相互关系,指出：（1）音高是语句重音的基本表达手段,随着语句重音级别的提高,音高分布曲线向高频方向推移。（2）在连续语流中词被‘重读”和“轻读”的情况下,音长分布出现双峰,表示它们的音长有的受语句重音的影响,有的不受语句重音的影响。（3）在“正常”、“重读”和“轻读”王种情况下,音高和音长的相互关系分别是：不相关、负相关和正相关,证实了汉语语句重音音高和音长之间的互补关系。这些研究结果为汉语会成系统中韵律模型的建立提供了基础。在此基础上,本文又用神经网络对连续语音的语句重音进行了部分标注,开集中的分类结果正确率为63％,对语音数据中重音等级的自动标注方法作了探索。     

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。      

语篇中大尺度信息单元边界的声学线索

主要研究了语篇中句子、段落等大尺度信息单元边界的韵律等级以及边界处的声学线索。对10个语篇语料库进行了韵律等级标注和声学分析。研究得到以下主要结论: (1)语篇中有韵律意义的大尺度信息单元有小句(对应语调短语)、句子(包括单句和复句)和段落。单句和复句边界没有知觉等级和声学特征上的显著区别,对应同一韵律单元。 (2)大尺度韵律边界等级的音高线索是通过边界前后音节的音高对比实现的,即音高重置程度。仅有首音节或末音节处的单一声学线索不足以区分边界等级。(3)段落和复句内的语调短语基本以平行的模式存在,没有明显的、规律性的整体语调下倾的现象。 (4)信息单元越大,无声段越长且变化的自由度越大。另外,在小句边界处无声段与音高重置程度显著正相关。     

汉语语句中重读音节音高变化模式研究

对汉语重读音节知觉的音高线索及句中重读音节的音高变化模式进行了研究。论文分3部分:重音知觉实验、问答匹配实验和语料库分析。重音知觉实验主要考察了重音知觉的音高线索,主要是高音点、低音点对重音知觉的贡献。重读音节音高变化模式的研究,一方面从发音人的角度,用问答匹配实验,选取/DAO4/为代表音节,设计少量实验句请多位发音人郎读,系统安排/DAO4/在句中的位置,用问句自然地引导/DAO4/重读或非重读,对这两种情况做比较;另一方面从听者的角度,用语料库分析,对一个大规模语料库通过感知实验进行重音和停顿两方面韵律标注,比较标为重和标为轻的音节的音高值。重音知觉实验结果表明,音域平移和高音点提高都是重音知觉的线索,但是高音点的提高对词重音知觉的作用更明显。重读音节音高变化模式的两项研究表明,重读音节的音高在高音线－低音线渐降汉语语调模式上变化,高音点的提高是重读音节音高变化的主要声学表现,低音点的变化更多地受到低音线渐降的限制,变化的幅度不十分明显,而且不足必须提高。高音线－低音线双线语调模型中,高音线起落的变化,前后音节高音点的对比关系表明句中音节的重读程度。     

连续话语中双音节韵律词的重音感知

对于从微软亚洲研究院的汉语语音语料库中获得的300个语句中的1,898个双音节韵律词进行了重音感知实验,实验结果表明,连续话语中双音节词的重音感知特点与孤立词的重音感知特点有所不同,它受到词所在的韵律边界的显著影响。在感知实验中,词内两音节的重音得分之差与它们的高音点音高差和时长差都表现出正相关,但与高音点音高差的相关强于与时长差的相关。高音点音高差和时长差在非停顿前不相关,在停顿前为较弱的正相关。实验结果还表明,音节的重音感知受到调型的显著影响。     

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。      

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。      

关于汉语音节知觉空间的实验研究

通过心理物理实验方法建构汉语音节知觉的多维空间结构,寻求有关汉语音节知觉的客观表现。结果表明,在声学特征层面上,音高和时长是音节知觉结构的主要维度;在韵律层面上,句中位置、韵律词长度等指标比较直观地反映了音节在知觉多维空间中的分布。     

The impact of discourse stress on clause prosody in Chinese Putonghua

By analyzing the acoustic data of a Chinese news report,the present research explores the pattern of how to change syllable duration and pitch of stress when isolated clauses are connected into a discourse.Comparing the same clause between isolated and in discourse context,the pitch variation of the clause nucleus can be most manifests,i.e.the top points as a whole fall remarkably;furthermore the degree of pitch falling varies with different kinds of stresses.When clause stresses are not assigned the status of discourse stress,they show a weakening effect of stress;it means pitch falling and syllable duration shortening.In a discourse composed of several clauses,speakers can modulate clause prosody by varying the strength of stresses;thereby realize the overall control of the discourse prosody and exact semantic expression.The findings on phonetic material from broadcast will shed light on the teaching of news broadcasting and contribute to the prosodic control of Chinese Putonghua synthesis.     

Study on automatic prediction of sentential stress for Chinese Putonghua Text-to-Speech system with natural style

Stress is an important parameter for prosody processing in speech synthesis. In this paper, we compare the acoustic features of neutral tone syllables and strong stress syllables with moderate stress syllables, including pitch, syllable duration, intensity and pause length after syllable. The relation between duration and pitch, as well as the Third Tone (T3) and pitch are also studied. Three stress prediction models based on ANN, i.e. the acoustic model, the linguistic model and the mixed model, are presented for predicting Chinese sentential stress. The results show that the mixed model performs better than the other two models. In order to solve the problem of the diversity of manual labeling, an evaluation index of support ratio is proposed.     

A text-to-speech system with high intelligibility and naturalness for Chinese

I.IntroductionResearchesonChinesesynthesisdisclosethatonlywhenboththesegmentalandsupraseg-melltalfeaturesofthesyntheticspeecharesimilartothoseofthellaturalone,thesyntheticspeechwillsoundintelligibleandnatural[1].Amongekistingsynthetictechniques,theapproachbasedonacousticparametersca-nadustboththesegmentalandsuprasegmentalfeaturesofsyntheticunitsfiekiblyandcanbeconsideredasthemostreasonablesynthetictechniqueintheory.However,theparameterbasedsynthesizerisoverAfependentonthedevelopmentsofparamet…     

The roles of pitch and duration in sentence accent of Chinese discourse

Relying on a corpus of thirty narrative discourses,the roles of pitch and duration of prosodic words in sentence accent were studied in discourse context.At first,the pitch was normalized.Then according to the pitch range,the sentence and prosodic word were classified into three ranks of strengthened,normal and weakened respectively.In the same time the sentence accent was classified into two levels of primary and secondary by perceptual evaluation. The results showed that the relative pitch range of prosodic words in opposition to sentence contributed dominantly to sentence accent.Furthermore,the roles of pitch and duration in sentence accent were affected interactively by the rank of sentence and prosodic words.In normal prosodic words,primary sentence accents were realized by the mutual performance of pitch and duration while secondary sentence accents mainly depended on the variation of pitch. In strengthened prosodic words,the role of duration in sentence accent was more significant when the pitch range of the sentence was more compressed.Finally,it was found that the correlation between pitch and duration was influenced primarily by the strength of prosodic words,and in weakened,normal and strengthened prosodic words,the correlations between pitch and duration were positive,null,and negative respectively.     

Experimental research on the perception space of Chinese syllable

The perceptive multi-dimension structure of Chinese syllables is studied by psychological-physical experiment. The results indicate that FO and duration are interrelated to two main dimensions of the perceptive structure of Chinese syllable. And the prosodic characteristics such as the position of syllable in prosodic hierarchical structure, as well as the stress will be induced the various distribution of syllable in perception space.     

The influence of discourse hierarchy on the acoustic manifestation of focus in standard Chinese

A phonetic experiment was conducted to investigate whether the acoustic features of discourse focus were subjected to the influence of discourse hierarchy.Six speakers were instructed to read aloud 32 groups of experimental material.The duration,pitch range,f0 maxima,and f0 minima of foci in different discourse hierarchies were extracted for statistical analysis.The results revealed that foci embedded higher in the discourse hierarchy had relatively longer duration and more expanded pitch range;moreover,with the variation of tone combination,foci in different discourse hierarchies differed remarkably in their manifestation of f0 maxima and f0 minima features.Specifically speaking,for non-low tone combinations, foci in higher discourse hierarchy were pronounced with higher f0 maxima,while for low-tone combinations,foci in higher discourse hierarchy were articulated with lower f0 minima.     

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.     

汉语和英语音高重音自动标注方法的对比与分析

虽然汉语和英语的重音自动标注被广泛的研究,但是关于汉语和英语的重音自动标注之间对比的研究还鲜有报道。基于汉语韵律标注库ASCCD和英语韵律标注库Boston University Radio News Corpus,对汉语和英语的重音自动标注的异同进行对比,考察不同的特征在不同语言的语料库上的泛化性能。通过基于集成分类回归树的重音自动标注实验、特征分析及基于互信息的重音自动标注的声学对比,得到如下结论:在相同的条件下,汉语重音自动标注的正确率比英语重音自动标注的正确率要低;在重音自动标注中,词典语法相关特征比声学相关的特征更重要;不同的声学信息源在重音自动标注中所起的作用不同,时长相关的特征对汉语和英语重音自动标注都很重要;英语中大部分特征提供的互信息要比汉语相应的特征提供的互信息要高。      

Post-low bouncing in Mandarin Chinese: acoustic analysis and computational modeling

Post-low bouncing is a phenomenon whereby after reaching a very low pitch in a low lexical tone, F(0) bounces up and then gradually drops back in the following syllables. This paper reports the results of an acoustic analysis of the phenomenon in two Mandarin Chinese corpora and presents a simple mechanical model that can effectively simulate this bouncing effect. The acoustic analysis shows that most of the F(0) dynamic features profiling the bouncing effect strongly correlate with the amount of F(0) lowering in the preceding low-tone syllable, and that the additional F(0) raising commences at the onset of the first post-low syllable. Using the quantitative Target Approximation model, this bouncing effect was simulated by adding an acceleration adjustment to the initial F(0) state of the first post-low syllable. A highly linear relation between F(0) lowering and estimated acceleration adjustment was found. This relation was then used to effectively simulate the bouncing effect in both the neutral tone and the full tones. The results of the analysis and simulation are consistent with the hypothesis that the bouncing effect is due to a temporary perturbation of the balance between antagonistic forces in the laryngeal control in producing a very low pitch.