Speech recognition with dynamic grammars using finite-state transducers

Abstract

Spoken language systems, ranging from interactive voice response (IVR) to mixed-initiative conversational systems, make use of a wide range of recognition grammars and vocabularies. The recognition grammars are either static (created at design time) or dynamic (dependent on database lookup at run time). This paper examines the compilation of recognition grammars with an emphasis on the dynamic (changing) properties of the grammar and how these relate to context-dependent speech recognizers. By casting the problem in the algebra of finite-state transducers (FSTs) we can use the composition operator for fast-and-efficient compilation and splicing of dynamic recognition grammars within the context of a larger precompiled static grammar.