Lattice-based MLLR for speaker recognition

Maximum-Likelihod Linear Regression (MLLR) transform coefficients have shown to be useful features for text-independent speaker recognition systems. These use MLLR coefficients computed on a Large Vocabulary Continuous Speech Recognition System (LVCSR) as features and Support Vector machines(SVM) classification. However, performance is limited by transcripts, which are often erroneous with high word error rates (WER) for spontaneous telephone speech applications. In this paper, we propose using lattice-based MLLR to overcome this issue. Using wordlattices instead of 1-best hypotheses, more hypotheses can be considered for MLLR estimation and, thus, better models are more likely to be used. As opposed to standard MLLR, language model probabilities are taken into account as well. We show how systems using lattice MLLR outperform standard MLLR systems in the Speaker Recognition Evaluation (SRE) 2006. Comparison to other standard acoustic systems is provided as well.