This paper proposes model-space Maximum Likelihood Linear Regression (mMLLR) based speaker adaptation technique for trajectory HMMs, which have been derived from HMMs by imposing explicit relationships between static and dynamic features. This model can alleviate two limitations of the HMM: constant statistics within a state and conditional independence assumption of state output probabilities without increasing the number of model parameters. Results in a continuous speech recognition experiments show that the proposed algorithm can adapt trajectory HMMs to a specific speaker and improve the performance of a trajectory HMM-based speech recognition system.
Bibliographic reference. Zen, Heiga / Nankaku, Yoshihiko / Tokuda, Keiichi (2007): "Model-space MLLR for trajectory HMMs", In INTERSPEECH-2007, 2065-2068.