Pronunciation Adaption at the Lexical Level
Helmer Strik · Radboud Repository (Radboud University) · 2001
T here are various kinds o f adaptation w hich can be used to enhance the perform ance o f autom atic speech recognizers.This paper is about pronunciation adaptation at the lexical level, i.e. about m odeling pronunciation variation at the lexical level.In the early years o f autom atic speech recognition (A S R ) research, the am ount o f pronunciation variation w as lim ited by using isolated w ords.Since the focus gradually shifted from isolated w ords to conversational speech, the am ount o f pronunciation variation present in the speech signals has increased, as has the need to m odel it.This is reflected by the grow ing attention for this topic.In this paper, an overview o f the studies on lexicon adaptation is presented.F urtherm ore, m any exam ples are m entioned o f situations in w hich lexicon adaptation is likely to im prove the perform ance o f speech recognizers.F inally, it is argued that som e assum ptions m ade in current standard A SR system s are not in line w ith the properties o f the speech signals.Consequently, the problem o f pronunciation variation at the lexical level probably cannot be solved by sim ply adding new transcriptions to the lexicon, as it is generally done at the m om ent.