Title
Discriminative Training Based on the Criterion of Least Phone Competing Tokens for Large Vocabulary Speech Recognition
Abstract
In this paper, we propose a new discriminative training approach based on the criterion of least phone competing tokens. In our approach, we first collect a competing token set for each physical HMM from training data. Different from the previous in-search token selection, an off-line token collection procedure is used in this work to collect the competing-tokens from word lattices. Then we re-estimate HMM parameters discriminatively to minimize the total number of competing tokens counted in the phone level. The phone token counts are approximated by a sigmoid-based objective function. The GPD algorithm is used to adjust HMM parameters to minimize the objective function. In this work, a merging mechanism and a gradient normalization in the HMM tied-state level are proposed to improve the generalization power of our discriminative training method. The proposed method is evaluated on the Resource Management (RM) and the Switchboard (a 24-hr mini-train set) tasks. Experimental results clearly show that our new discriminative training method achieves significant improvements over our best MLE models in both tasks, namely about 8% and 4.5% relative error rate reduction in RM and Switchboard respectively, over the best MLE models. © 2005 IEEE.
Year
DOI
Venue
2005
10.1109/ICASSP.2005.1415064
ICASSP (1)
Keywords
DocType
Volume
competing token set,off-line token collection procedure,least phone competing tokens,speech recognition,learning (artificial intelligence),relative error rate reduction,acoustic models,hmm,large vocabulary speech recognition,merging mechanism,discriminative training method,gradient normalization,gradient methods,gpd algorithm,word lattices,hidden markov models,sigmoid-based objective function minimization,merging,maximum likelihood estimation,lattices,automatic speech recognition,learning artificial intelligence
Conference
1
Issue
ISSN
ISBN
null
1520-6149
0-7803-8874-7
Citations 
PageRank 
References 
2
0.48
6
Authors
4
Name
Order
Citations
PageRank
Bo Liu120.48
Hui Jiang21493113.16
Jian-Lai Zhou318420.85
Ren-Hua Wang434441.36