A sub-word based speaker independent speech recognizer using a two-pass segmentation scheme

An isolated-word speech recognizer based on acoustically defined subwords is described. In the training stage the speech is decomposed by an automatic two-pass segmentation algorithm. In the first pass the subword boundaries are estimated. The second pass divides each subword into three subsegments, thus matching the states in the three-state HMMs used to model the subwords. On the basis of both the segmental and subsegmental information, the acoustic lexicon and the HMMs are created. Used in a speaker-independent mode the recognizer is slightly inferior to a corresponding whole-word-based recognizer