Evaluation on unsupervised speaker adaptation based on sufficient HMM statictics of selected speakers

This paper describes an efficient method of unsupervised speaker adaptation. This method is based on (1) selecting a subset of speakers who are acoustically close to a test speaker, and (2) calculating adapted model parameters according to the previously stored sufficient statistics of the selected speakers’ data. In this method, only a few unsupervised test speaker’s data are necessary for the adaptation. Also, by using the sufficient HMM statistics of the selected speakers’ data, a quick adaptation can be done. Compared with a pre-clustering method, the proposed method can obtain a more optimal cluster because the clustering result is determined according to test speaker’s data on-line. Experimental results show that the proposed method attains better improvement than MLLR from the speaker-independent model. The proposed method is evaluated in details and discussed.