The production of prosodic focus and contour in dialogue

Computer programs designed to converse with humans in natural language provide a framework against which to test supra-sentential theories of language production and interpretation. This thesis seeks to flesh out, in terms of a computer model, two basic assumptions concerning prosody-that speakers use intonation to convey intention, or attitude, and that prosodic prominence serves to convey conceptual prommence. A model of an information-providing agent in is proposed, based on an analysis of a corpus of spontaneous dialogues. This uses an architecture of communicating processes, which perform interpretation, application-specific planning, repair, and the production of output. Dialogue acts are then defined as feature bundles corresponding to significant events. A corpus of read dialogues is analysed in terms of these features, and using conventional intonational labelling. Correlations between the two are examined. Prosodic prominence is examined at three levels. At the level of surface encoding, re-use of substrings and structural parallelism can reduce processing for the speaker, and the listener. At the level of conceptual planning, similar benefits exist, given that speakers and listeners assume a common discourse model wherever possible. At these levels use is made of a short-term buffer of recent forms. A speaker may additionally use contrastive prominence to draw the listener's attention to disparities. Finally, at the level of intentions, a speaker wish to highlight certain information, regardless of accessibility. Prosodic focus is represented relationally, rather than via a simple binary-valued feature. This has the advantage of facilitating the mapping between levels; it also renders straightforward the notion of focus as the product of a number of potentially conflicting influences. Those parts of the theory concerned with discourse representation, language generation, and prosodic focus have been implemented as part of the Sundial dialogue system. In this system, discoursal and pragmatic decisions affecting prosody are converted to annotations on a text string, for realisation by a rule-based synthesizer

Products and Services

Today’s global economy offers more opportunities, but is also more complex and competitive than ever before. This fact leads to a wide range of research activity in different fields of interest, especially in the so-called high-tech sectors. This book is a result of widespread research and development activity from many researchers worldwide, covering the aspects of development activities in general, as well as various aspects of the practical application of knowledge

Understanding the phonetics of neutralisation: a variability-field account of vowel/zero alternations in a Hijazi dialect of Arabic

This thesis throws new light on issues debated in the experimental literature on neutralisation. They concern the extent of phonetic merger (the completeness question) and the empirical validity of the phonetic effect (the genuineness question). Regarding the completeness question, I present acoustic and perceptual analyses of vowel/zero alternations in Bedouin Hijazi Arabic (BHA) that appear to result in neutralisation. The phonology of these alternations exemplifies two neutralisation scenarios bearing on the completeness question. Until now, these scenarios have been investigated separately within small-scale studies. Here I look more closely at both, testing hypotheses involving the acoustics-perception relation and the phonetics-phonology relation. I then discuss the genuineness question from an experimental and statistical perspective. Experimentally, I devise a paradigm that manipulates important variables claimed to influence the phonetics of neutralisation. Statistically, I reanalyse neutralisation data reported in the literature from Turkish and Polish. I apply different pre-analysis procedures which, I argue, can partly explain the mixed results in the literature. My inquiry into these issues leads me to challenge some of the discipline’s accepted standards for characterising the phonetics of neutralisation. My assessment draws on insights from different research fields including statistics, cognition, neurology, and psychophysics. I suggest alternative measures that are both cognitively and phonetically more plausible. I implement these within a new model of lexical representation and phonetic processing, the Variability Field Model (VFM). According to VFM, phonetic data are examined as jnd-based intervals rather than as single data points. This allows for a deeper understanding of phonetic variability. The model combines prototypical and episodic schemes and integrates linguistic, paralinguistic, and extra-linguistic effects. The thesis also offers a VFM-based analysis of a set of neutralisation data from BHA. In striving for a better understanding of the phonetics of neutralisation, the thesis raises important issues pertaining to the way we approach phonetic questions, generate and analyse data, and interpret and evaluate findings

Head-Driven Phrase Structure Grammar

Head-Driven Phrase Structure Grammar (HPSG) is a constraint-based or declarative approach to linguistic knowledge, which analyses all descriptive levels (phonology, morphology, syntax, semantics, pragmatics) with feature value pairs, structure sharing, and relational constraints. In syntax it assumes that expressions have a single relatively simple constituent structure. This volume provides a state-of-the-art introduction to the framework. Various chapters discuss basic assumptions and formal foundations, describe the evolution of the framework, and go into the details of the main syntactic phenomena. Further chapters are devoted to non-syntactic levels of description. The book also considers related fields and research areas (gesture, sign languages, computational linguistics) and includes chapters comparing HPSG with other frameworks (Lexical Functional Grammar, Categorial Grammar, Construction Grammar, Dependency Grammar, and Minimalism)