Pre-Low Raising in Japanese Pitch Accent

Japanese has been observed to have 2 versions of the H tone, the higher of which is associated with an accented mora. However, the distinction of these 2 versions only surfaces in context but not in isolation, leading to a long-standing debate over whether there is 1 H tone or 2. This article reports evidence that the higher version may result from a pre-low raising mechanism rather than being inherently higher. The evidence is based on an analysis of F0 of words that varied in length, accent condition and syllable structure, produced by native speakers of Japanese at 2 speech rates. The data indicate a clear separation between effects that are due to mora-level preplanning and those that are mechanical. These results are discussed in terms of mechanisms of laryngeal control during tone production, and highlight the importance of articulation as a link between phonology and surface acoustics.postprin

Toward invariant functional representations of variable surface fundamental frequency contours: Synthesizing speech melody via model-based stochastic learning

Variability has been one of the major challenges for both theoretical understanding and computer synthesis of speech prosody. In this paper we show that economical representation of variability is the key to effective modeling of prosody. Specifically, we report the development of PENTAtrainer—A trainable yet deterministic prosody synthesizer based on an articulatory–functional view of speech. We show with testing results on Thai, Mandarin and English that it is possible to achieve high-accuracy predictive synthesis of fundamental frequency contours with very small sets of parameters obtained through stochastic learning from real speech data. The first key component of this system is syllable-synchronized sequential target approximation—implemented as the qTA model, which is designed to simulate, for each tonal unit, a wide range of contextual variability with a single invariant target. The second key component is the automatic learning of function-specific targets through stochastic global optimization, guided by a layered pseudo-hierarchical functional annotation scheme, which requires the manual labeling of only the temporal domains of the functional units. The results in terms of synthesis accuracy demonstrate that effective modeling of the contextual variability is the key also to effective modeling of function-related variability. Additionally, we show that, being both theory-based and trainable (hence data-driven), computational systems like PENTAtrainer can serve as an effective modeling tool in basic research, with which the level of falsifiability in theory testing can be raised, and also a closer link between basic and applied research in speech science can be developed

How tone, intonation and emotion shape the development of infants' fundamental frequency perception

Fundamental frequency (ƒ0), perceived as pitch, is the first and arguably most salient auditory component humans are exposed to since the beginning of life. It carries multiple linguistic (e.g., word meaning) and paralinguistic (e.g., speakers’ emotion) functions in speech and communication. The mappings between these functions and ƒ0 features vary within a language and differ cross-linguistically. For instance, a rising pitch can be perceived as a question in English but a lexical tone in Mandarin. Such variations mean that infants must learn the specific mappings based on their respective linguistic and social environments. To date, canonical theoretical frameworks and most empirical studies do not view or consider the multi-functionality of ƒ0, but typically focus on individual functions. More importantly, despite the eventual mastery of ƒ0 in communication, it is unclear how infants learn to decompose and recognize these overlapping functions carried by ƒ0. In this paper, we review the symbioses and synergies of the lexical, intonational, and emotional functions that can be carried by ƒ0 and are being acquired throughout infancy. On the basis of our review, we put forward the Learnability Hypothesis that infants decompose and acquire multiple ƒ0 functions through native/environmental experiences. Under this hypothesis, we propose representative cases such as the synergy scenario, where infants use visual cues to disambiguate and decompose the different ƒ0 functions. Further, viable ways to test the scenarios derived from this hypothesis are suggested across auditory and visual modalities. Discovering how infants learn to master the diverse functions carried by ƒ0 can increase our understanding of linguistic systems, auditory processing and communication functions

Chapter 2: The Original ToBI System and the Evolution of the ToBI Framework

In this chapter, the authors will try to identify the essential properties of a ToBI framework annotation system by describing the development and design of the original ToBI conventions. In this description, the authors will overview the general phonological theory and the specific theory of Mainstream American English intonation and prosody that the authors decided to incorporate in the original ToBI tags. The authors will also state the practical principles that led us to make the decisions that the authors did. The chapter is organised as follows. Section 2.2 briefly chronicles how the MAE_ToBI system came into being. Section 2.3 briefly describes the consensus account of English intonation and prosody on which the MAE_ToBI system is based. Section 2.4 catalogues the different components of a MAE_ToBI transcription and lists the salient rules which constrain the relationships between different components. This section also expands upon the theoretical foundations and practical consequences of adopting the general structure of multiple labelling tiers, and particularly the separation of the labels for tones from the labels for indexing prosodic boundary strength. Section 2.5 then describes some of the extensions of the basic ToBI tiers that have been adopted by some sites. This section also compares our decisions about the number of tiers and about inter-tier constraints with the analogous decisions for some of the other ToBI systems described in this book. Section 2.6 discusses the status of the symbolic labels relative to the continuous phonetic records that are also an obligatory component of the MAE_ToBI transcription. Section 2.7 then closes by listing several open research questions that the authors would like to see addressed by MAE_ToBI users and the larger ToBI community

The dynamics of Japanese prosody

This dissertation explores aspects of Tokyo Japanese (Japanese henceforth) prosody through acoustic analysis and analysis-by-synthesis. It 1) revisits existing issues in Japanese prosody with the minimal use of abstract notions and 2) tests if the Parallel Encoding and Target Approximation (Xu, 2005) framework is suitable for Japanese, a pitch accent language. The first part of the dissertation considers the nature of lexical pitch accent through examining factors that affect the surface F0 realisation of an accent peak (Chapter 2) and establishing the articulatory domain that hosts a tonal target in Japanese (Chapter 3). Next, pitch accent interactions with other communicative functions are considered, specifically in terms of focus (Chapter 4) and sentence type (Chapter 5). Hypotheses using acoustic analyses from the previous Chapters are then verified through analysis-by-synthesis with articulatory synthesisers AMtrainer, PENTAtrainer1, and PENTAtrainer2 (Chapter 6). Chapter 2 provides conclusive evidence of Japanese as a two-tone language as opposed to bearing three underlying tones in its phonology, previously unresolved in existing literature. Proponents of the two-tone hypothesis gather evidence from perception: when stimuli are played in isolation, native listeners can only distinguish two tone levels (High and Low). On the other hand, production evidence reveals robustly three distinct surface F0 levels. Using a series of linear regression analyses, I show the third tone level could be interpreted as a result of pre-low raising, a common articulatory phenomenon. The F0 of an accent peak is inversely correlated with the F0 of the following low target, being an enhanced peak in preparation for the upcoming L. Interpreted together with native listeners’ inability to hear three tones when said in isolation, as repeatedly reported in previous studies, I establish Japanese has only H and L in its tonal inventory. Chapter 3 establishes the syllable as the tone-bearing unit in Japanese tonal articulation. Often described as a mora-timed language, it has been previously unclear whether articulatory tonal targets are hosted in a mora or a syllable in Japanese. When comparing accented words of various syllable structures I found that the F0 accent peak of CVCV wordsoccurs consistently earlier than that of CVn/CVCV words. CVCV words are longer in total duration so its earlier F0 peak is a result of a shorter tone-bearing unit (i.e. two consecutive short morae/syllables). CVn/CVV words on the other hand have a later peak F0 due to hosting an articulatory target as a long syllable, rather than two short morae. I further verified the syllable hypothesis using two articulatory synthesisers, PENTAtrainer1 and PENTAtrainer2. The syllable as a tone-bearing unit incurs fewer predictors but provides better learning accuracy. Chapter 4 explores focus prosody in declarative sentences. Using a newly collected corpus of 6251 sentences that controls for accent condition, focus condition, sentence type, and sentence length, I challenge the widely held idea that post-focus compression of F0 range is accent-independent. Currently it is generally accepted that regardless of the accent condition of the focused word, the excursion size of ‘initial rise’ that marks the beginning of the first word 4 after focus is shrunken. However, confining the notion of post-focus compression to initial-rise (usually extending across only two morae) sets Japanese apart from other languages like English or Mandarin, where such compression is robust across the entire post-focus domain. I show that when F0 range is measured across a wider domain, compression is absent. Where post-focus compression is absent, the F0 trajectory appears to be a result of articulatory carryover effects. This will be interpreted as a result of weak articulatory strength on the post focus domain, explaining the difference in F0 trajectories in long and short utterances. Chapter 5 builds on the previous Chapter to consider in addition the focus prosody in yes/no questions. I investigate what marks a yes/no question, and how focus prosody differs in declarative and interrogative utterances. Acoustic analyses show that questions are marked by a final rise, but the exact shape of such a rise depends on the accent condition of the sentence-final word. When compared to declarative sentences, the key differences in yes/no questions include: a higher F0 level; the absence of post-focus compression even in contexts otherwise observed in statements; and on-focus F0 raising as the only robust focus marker. These findings point to the fact that interrogative focus prosody is not an amalgamation of focus markers and question markers, and bear implication on the representation of Japanese intonation. Chapter 6 verifies observations established thus far through analysis-by-synthesis. I demonstrate comparative modeling as a means to adjudicate between competing theories using PENTAtrainer2, PENTAtrainer1 and AMtrainer. In terms of local fitting accuracy, AMtrainer yielded comparable synthesis accuracy to the PENTAtrainers. Finally, I further demonstrate the compatibility of PENTA with Japanese prosody showing highly accurate F0 predictive analysis (when trained with Chapter 2 production data), and highly satisfactory speaker-dependent synthesis accuracy (when trained with Chapter 4 and 5 sentential data). Naturalness judgment ratings show that the natural stimuli sound as natural as the synthetic stimuli, though questions generally sound less natural than statements. Reasons for this discrepancy are discussed with reference to the design of the stimuli

Stylisation of Thai tones using Prosogram

The aim of this study is to establish whether stylisation of F0 contours based on d'Alessandro and Mertens's model of tonal perception can be successfully applied to lexical tones of Central Thai. The percentage of correct responses to the manipulated stimuli was found to be significantly lower than the results for natural tones reported in literature on the subject.The aim of this study is to establish whether stylisation of F0 contours based on d'Alessandro and Mertens's model of tonal perception can be successfully applied to lexical tones of Central Thai. The percentage of correct responses to the manipulated stimuli was found to be significantly lower than the results for natural tones reported in literature on the subject

Prosody analysis and modeling for Cantonese text-to-speech.

Li Yu Jia.Thesis (M.Phil.)--Chinese University of Hong Kong, 2003.Includes bibliographical references.Abstracts in English and Chinese.Chapter Chapter 1 --- Introduction --- p.1Chapter 1.1. --- TTS Technology --- p.1Chapter 1.2. --- Prosody --- p.2Chapter 1.2.1. --- What is Prosody --- p.2Chapter 1.2.2. --- Prosody from Different Perspectives --- p.3Chapter 1.2.3. --- Acoustical Parameters of Prosody --- p.3Chapter 1.2.4. --- Prosody in TTS --- p.5Chapter 1.2.4.1 --- Analysis --- p.5Chapter 1.2.4.2 --- Modeling --- p.6Chapter 1.2.4.3 --- Evaluation --- p.6Chapter 1.3. --- Thesis Objectives --- p.7Chapter 1.4. --- Thesis Outline --- p.7Reference --- p.8Chapter Chapter 2 --- Cantonese --- p.9Chapter 2.1. --- The Cantonese Dialect --- p.9Chapter 2.1.1. --- Phonology --- p.10Chapter 2.1.1.1 --- Initial --- p.11Chapter 2.1.1.2 --- Final --- p.12Chapter 2.1.1.3 --- Tone --- p.13Chapter 2.1.2. --- Phonological Constraints --- p.14Chapter 2.2. --- Tones in Cantonese --- p.15Chapter 2.2.1. --- Tone System --- p.15Chapter 2.2.2. --- Linguistic Significance --- p.18Chapter 2.2.3. --- Acoustical Realization --- p.18Chapter 2.3. --- Prosodic Variation in Continuous Cantonese Speech --- p.20Chapter 2.4. --- Cantonese Speech Corpus - CUProsody --- p.21Reference --- p.23Chapter Chapter 3 --- F0 Normalization --- p.25Chapter 3.1. --- F0 in Speech Production --- p.25Chapter 3.2. --- F0 Extraction --- p.27Chapter 3.3. --- Duration-normalized Tone Contour --- p.29Chapter 3.4. --- F0 Normalization --- p.30Chapter 3.4.1. --- Necessity and Motivation --- p.30Chapter 3.4.2. --- F0 Normalization --- p.33Chapter 3.4.2.1 --- Methodology --- p.33Chapter 3.4.2.2 --- Assumptions --- p.34Chapter 3.4.2.3 --- Estimation of Relative Tone Ratios --- p.35Chapter 3.4.2.4 --- Derivation of Phrase Curve --- p.37Chapter 3.4.2.5 --- Normalization of Absolute FO Values --- p.39Chapter 3.4.3. --- Experiments and Discussion --- p.39Chapter 3.5. --- Conclusions --- p.44Reference --- p.45Chapter Chapter 4 --- Acoustical FO Analysis --- p.48Chapter 4.1. --- Methodology of FO Analysis --- p.48Chapter 4.1.1. --- Analysis-by-Synthesis --- p.48Chapter 4.1.2. --- Acoustical Analysis --- p.51Chapter 4.2. --- Acoustical FO Analysis for Cantonese --- p.52Chapter 4.2.1. --- Analysis of Phrase Curves --- p.52Chapter 4.2.2. --- Analysis of Tone Contours --- p.55Chapter 4.2.2.1 --- Context-independent Single-tone Contours --- p.56Chapter 4.2.2.2 --- Contextual Variation --- p.58Chapter 4.2.2.3 --- Co-articulated Tone Contours of Disyllabic Word --- p.59Chapter 4.2.2.4 --- Cross-word Contours --- p.62Chapter 4.2.2.5 --- Phrase-initial Tone Contours --- p.65Chapter 4.3. --- Summary --- p.66Reference --- p.67Chapter Chapter5 --- Prosody Modeling for Cantonese Text-to-Speech --- p.70Chapter 5.1. --- Parametric Model and Non-parametric Model --- p.70Chapter 5.2. --- Cantonese Text-to-Speech: Baseline System --- p.72Chapter 5.2.1. --- Sub-syllable Unit --- p.72Chapter 5.2.2. --- Text Analysis Module --- p.73Chapter 5.2.3. --- Acoustical Synthesis --- p.74Chapter 5.2.4. --- Prosody Module --- p.74Chapter 5.3. --- Enhanced Prosody Model --- p.74Chapter 5.3.1. --- Modeling Tone Contours --- p.75Chapter 5.3.1.1 --- Word-level FO Contours --- p.76Chapter 5.3.1.2 --- Phrase-initial Tone Contours --- p.77Chapter 5.3.1.3 --- Tone Contours at Word Boundary --- p.78Chapter 5.3.2. --- Modeling Phrase Curves --- p.79Chapter 5.3.3. --- Generation of Continuous FO Contours --- p.81Chapter 5.4. --- Summary --- p.81Reference --- p.82Chapter Chapter 6 --- Performance Evaluation --- p.83Chapter 6.1. --- Introduction to Perceptual Test --- p.83Chapter 6.1.1. --- Aspects of Evaluation --- p.84Chapter 6.1.2. --- Methods of Judgment Test --- p.84Chapter 6.1.3. --- Problems in Perceptual Test --- p.85Chapter 6.2. --- Perceptual Tests for Cantonese TTS --- p.86Chapter 6.2.1. --- Intelligibility Tests --- p.86Chapter 6.2.1.1 --- Method --- p.86Chapter 6.2.1.2 --- Results --- p.88Chapter 6.2.1.3 --- Analysis --- p.89Chapter 6.2.2. --- Naturalness Tests --- p.90Chapter 6.2.2.1 --- Word-level --- p.90Chapter 6.2.2.1.1 --- Method --- p.90Chapter 6.2.2.1.2 --- Results --- p.91Chapter 6.2.3.1.3 --- Analysis --- p.91Chapter 6.2.2.2 --- Sentence-level --- p.92Chapter 6.2.2.2.1 --- Method --- p.92Chapter 6.2.2.2.2 --- Results --- p.93Chapter 6.2.2.2.3 --- Analysis --- p.94Chapter 6.3. --- Conclusions --- p.95Chapter 6.4. --- Summary --- p.95Reference --- p.96Chapter Chapter 7 --- Conclusions and Future Work --- p.97Chapter 7.1. --- Conclusions --- p.97Chapter 7.2. --- Suggested Future Work --- p.99Appendix --- p.100Appendix 1 Linear Regression --- p.100Appendix 2 36 Templates of Cross-word Contours --- p.101Appendix 3 Word List for Word-level Tests --- p.102Appendix 4 Syllable Occurrence in Word List of Intelligibility Test --- p.108Appendix 5 Wrongly Identified Word List --- p.112Appendix 6 Confusion Matrix --- p.115Appendix 7 Unintelligible Word List --- p.117Appendix 8 Noisy Word List --- p.119Appendix 9 Sentence List for Naturalness Test --- p.12