5th International Conference on Spoken Language Processing
This paper presents a novel framework of on-line hierarchical transformation of hidden Markov models (HMM's) for speaker adaptation. Our aim is to incrementally transform (or adapt) all the HMM parameters to a new speaker even though part of HMM units are unseen in adaptation data. The transformation paradigm is formulated according to the approximate Bayesian estimate, which the prior statistics and the transformation parameters are incrementally updated for each consecutive adaptation data. Using this formulation, the updated prior statistics and the current block of data are sufficient for on-line transformation. Further, we establish a hierarchical tree of HMM's and use it to dynamically control the transformation sharing for each HMM unit. In the speaker adaptation experiments, we demonstrate the superiority of proposed on-line transformation to other method.
Bibliographic reference. Chien, Jen-Tzung (1998): "On-line hierarchical transformation of hidden Markov models for speaker adaptation", In ICSLP-1998, paper 0102.