International Symposium on Chinese Spoken Language Processing
August 23-24, 2002
Two-Pass Continuous Digit String Decoder
Zhi-yu Wang, Yuan Wen, Ming Li
Institute of Acoustics,
Chinese Academy of Sciences, Beijing
In this paper, we present a two-pass continuous digit string
decoder using two sets of whole-word HMM models. One
set contains context-independent (CI) models used in the
first-pass search. The first-pass search results in N-best
hypotheses from which a N-best word lattice can be derived.
The other set contains context-dependent (CD) HMM
models used to search along the N-best word lattice for the
best hypothesis, which is called the second-pass search.
During the second-pass search, we introduce a
tree-structured word lattice to speed up the second-pass
search. Compared with one-pass decoder using only CI
models, our two-pass decoder achieves 68% reduction of
word error rate. Compared with one-pass decoder using only
CD models, it achieves a 6.5 times faster search speed.
Compared with two-pass decoder using flat-structured word
lattice, it achieves about one time faster search speed.
Wang, Zhi-yu / Wen, Yuan / Li, Ming (2002):
"Two-pass continuous digit string decoder",
In ISCSLP 2002, paper 13.