19 Nov
1999
Sphinx
Speech Group, CMU-SCS (rkm@cs.cmu.edu)
Post-Lextree LM Evaluation (Sphinx-II)
·Single
lextree
·Null
transitions from leaf nodes back to root nodes
·No
LM score upon transition into root or non-leaf node of lextree
·If
reached a leaf node for word W:
·Find
all possible LM histories of W
(from BP table)
·Find
LM scores for W
w.r.t. each LM history
·Choose
best resulting path-score for W
·Drawbacks:
·Inexact
acoustic scores
·Root node evaluated w.r.t. a single left
context, but resulting score used w.r.t. all histories (with possibly different
left contexts)
·Impoverished
word segmentations