5th European Conference on Speech Communication and Technology

Rhodes, Greece
September 22-25, 1997

Transducer Composition for Context-Dependent Network Expansion

Michael Riley, Fernando Pereira, Mehryar Mohri

AT&T Labs-Research, Florham Park, NJ, USA

Context-dependent models for language units are essential in high-accuracy speech recognition. However, standard speech recognition frameworks are based on the substitution of level models for higher-level units. Since substitution cannot express context-dependency constraints, actual recognizers use restrictive model-structure assumptions and specialized code for context-dependent models, leading to decreased flexibility and lost opportunities for automatic model optimization. Instead, we propose a recognition framework that builds in the possibility of context dependency from the start by using weighted finite-state transduction rather than substitution. The framework is mented with a general demand-driven transducer composition algorithm that allows great flexibility in model structure, form of context dependency and network expansion method, while achieving competitive recognition performance.

Full Paper

Bibliographic reference.  Riley, Michael / Pereira, Fernando / Mohri, Mehryar (1997): "Transducer composition for context-dependent network expansion", In EUROSPEECH-1997, 1427-1430.