One-Level Phonology: Autosegmental Representations and Rules as Finite Automata

When phonological rules are regarded as declarative descriptions, it is possible to construct a model of phonology in which rules and representations are no longer distinguished and such procedural devices as rule-ordering are absent. In 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.