Current-generation automatic speech recognition (ASR) systems model spoken discourse as a linear sequence of words and phones. Because it is unusual for every phone within a word to be pronounced in a standard ("canonical") way, ASR systems often depend on a multi-pronunciation lexicon to match an acoustic sequence with a lexical unit. Since there are, in practice, many different ways for a word to be pronounced, this standard approach adds a layer of complexity and ambiguity to the decoding process which, if modified, could potentially improve recognition performance. Systematic analysis of pronunciation variation in a corpus of spontaneous English discourse (Switchboard) demonstrates that the variation observed is systematic at the level of the syllable. Syllabic onsets are realized in canonical form far more frequently than either coda or nuclear constituents. Prosodic stress also plays an important role in pronunciation. The governing mechanism is likely to involve the informationa...

T he distinction between marked and unmarked structures has played a role throughout this century in the development of phonology and of linguistics generally. Optimality Theory (Prince and Smolensky 1993) offers an approach to linguistic theory that aims to combine an empirically adequate theory of

Declarative phonology is a program of research that was motivated in part by the need for theories of phonology that can be implemented on a computer. While it is clear that such a development would be beneficial for both theoretical and field phonology, it is not immediately obvious how one should go about implementing phonological models. The

this paper we present a finite-state model of phonology in which automata are the descriptions and tapes (or strings) are the objects being described. This provides the formal semantics for an autosegmental phonology without structure-changing rules. Logical operations on the phonological domain--such as conjunction, disjunction, and negation--make sense since the phonological domain consists of descriptions rather than objects. These operations as applied to automata are the straightforward operations of intersection, union, and complement. If the arrow in a rewrite rule is viewed as logical implication, then a phonological rule can also be represented as an automaton, albeit a less restrictive automaton than would be required for a lexical representation. The model is then compared with the transducer models for autosegmental phonology of Kay (1987), Kornai (1991), and Wiebe (1992). We conclude that the declarative approach to phonology presents an attractive way of extending finite-state techniques to autosegmental phonology while remaining within the confines of regular grammar

this paper we suggest some strategies for reuniting phonology and the rest of grammar in the context of a uniform constraint formalism. We explain why this is a desirable goal, and we present some conservative extensions to current practice in computational linguistics and in non-linear phonology which we believe are necessary and sufficient for achieving this goal. We begin by exploring the application of typed feature logic to phonology and propose a system of prosodic types. Next, taking HPSG as an exemplar of the grammar frameworks we have in mind, we show how the phonology attribute can be enriched, so that it can encode multi-tiered, hierarchical phonological representations. Finally, we exemplify the approach in some detail for the nonconcatenative morphology of Sierra Miwok and for schwa alternation in French. The approach taken in this paper lends itself particularly well to capturing phonological generalisations in terms of high-level prosodic constraints. 1. Phonology in Constraint-Based Grammar Classical generative phonology is couched within the same set of assumptions that dominated standard transformational grammar. Despite some claims that "derivations based on ordered rules (that is, external ordering) and incorporating intermediate structures are essential to phonology" (Bromberger & Halle, 1989:52), much recent work has tended towards a new model, frequently described in terms of constraints on well-formedness (Paradis, 1988; Goldsmith, 1993; McCarthy & Prince, 1993; Prince & Smolensky, 1993). While this work has an increasingly declarative flavour, most versions retain procedural devices for repairing representations that fail to meet certain constraints, or for constraints to override each other. This view is in marked contrast to the interpretation...

this article will be to explain some of the alternations and distributional asymmetries in terms of syllable structure. The only consonant clusters which occur have the form (N)C(G)(h) where N is a homorganic nasal and G is a glide, or have the form (N)OL, where O is an obstruent and L is a liquid, as is characteristic of Niger-Congo languages in general (Maddieson 1981:89). Some complex articulations have not been entered into (3) since they are treated as sequences. The trill r only occurs in loanwords, while the flap D

This paper offers a provisional mathemat~ ical typology of metrical representations.

The derivational view of phonetics-phonology (Ladd, this volume) expresses an intuition that seems valid, namely, that there is a distinction to be made between quantitative and qualitative aspects of phonetics-phonology. Incomplete neutralization (Ernestus and Baayen, this volume) and other phenomena like it indicate that the specific way of drawing that distinction is too rigid. At the same time, these phenomena underscore the need for a different formal language, where discrete and continuous aspects of phonetics-phonology can interact. A way of reconciling the core intuition of the derivational view with phenomena like incomplete neutralization is proposed using the mathematics of nonlinear dynamics. This allows one to integrate the continuous and the discrete without the additional postulate that phonology is derivationally antecedent to phonetics. 1. Two views of phonetics-phonology How are the qualitative aspects of phonological competence related to their variable and continuous phonetic manifestation? This question defines the so-called ‘phonetics-phonology problem ’ and it has been one of the central themes of laboratory phonology (Beckman and Kingston 1990: 1). It is also an instance of a broader question in cognitive science, namely, the question of how to relate the low dimensional, discrete aspects of cognition to the high dimensional aspects of performance, as shown by parallel research in vision (Haken 1990), coordination in action (Turvey 1990), agent-environment interaction (Beer 1995) and other domains. There are two broad views on the formalization of theories aiming to address this central question. One view, firmly established with the development of generative phonology (Chomsky and Halle 1968) and subsequently elaborated and refined in important ways (Liberman and Pierrehumbert 1984;

. An implemented approach which couples a constraint-based phonology component with an articulatory speech synthesizer is proposed. Articulatory gestures ensure a tight connection between both components, as they comprise both physical-phonetic and phonological aspects. The phonological modelling of e.g. syllabification and phonological processes such as German final devoicing is expressed in the constraint logic programming language CUF. Extending CUF by arithmetic constraints allows the simultaneous description of both phonology and phonetics. Thus declarative lexicalist theories of grammar such as HPSG may be enriched up to the level of detailed phonetic realisation. Initial acoustic demonstrations show that our approach is in principle capable of synthesizing full utterances in a linguistically motivated fashion. 1 Introduction Within the last few years it has been stressed in the field of machine speech recognition and synthesis that one should incorporate genuine lin...

nition, and is undesirable even in generationsbased applications, such as textto -speech. However, this has not preveuted the pearance of a nmnber of "linguistic rule compilers" such as Van Leenwen's (1987, 1989) and Hertzs sys.- rems. The basic operations of a transformational gram mar -- deletion, insertion, permutation, and copying -- are apparently empirically instantiated by such well-established phonological phenemona as elision, epenthesis, metathesis, assimilation and coarticula- tion. Copying (i): Assimilation e.g. I ran [n] ran quickly [ ] rtule: n-u/ {k,g} [I)] denotes back-of-tongue (velar) nasal closure e.g. 2 sandwich [samwit f] Rule: n - m/ {p,b,w etc.) 79 Copying (ii): Coarticulation e.g. keep cool cart [_k] denotes advanced articulation denotes lip-rounding denotes retracted articulation Insertion: Epenthesis e.g, mince [mints] pence [pents] Rule: ns- nts Deletion: Elision e.g. sandwich [sanWit f] Rule: nd -- n Permutation: Metathesis e.g. burnt