Acoustic scores and symbolic mismatch penalties in phone lattices
ten Bosch, L., Hämäläinen, A., Scharenborg, O., & Boves, L.
Acoustic scores and symbolic mismatch penalties in phone lattices. In Proceedings of the 2006 IEEE International Conference on Acoustics, Speech and Signal Processing [ICASSP 2006]
This paper builds on previous work that aims at unraveling the structure of the speech signal by means of using probabilistic representations. The context of this work is a multi-pass speech recognition system in which a phone lattice is created and used as a basis for a lexical search in which symbolic mismatches are allowed at certain costs. The focus is on the optimization of the costs of phone insertions, deletions and substitutions that are used in the lexical decoding pass. Two optimization approaches are presented, one related to a multi-pass computational model for human speech recognition, the other based on a decoding in which Bayes’ risks are minimized. In the final section, the advantages of these optimization methods are discussed and compared.