8th International Conference on Spoken Language Processing

Jeju Island, Korea
October 4-8, 2004

Decision-Tree Backing-off in HMM-based Speech Synthesis

Shunsuke Kataoka, Nobuaki Mizutani, Keiichi Tokuda, Tadashi Kitamura

Nagoya Institute of Technology, Japan

This paper proposes a decision-tree backing-off technique for an HMM-based speech synthesis system. In the system, a decision-tree based context clustering technique is used for constructing parameter tying structures. In the context clustering, the MDL criterion has been used as a stopping criterion. In this paper, however, huge decision-trees are constructed without any stopping criterion. In the synthesis phase, decision-trees obtained in this way are used in the proposed backing-off scheme. This enables us to adjust the cluster size dynamically at run-time according to the text to be synthesized. Results of subjective listening tests show that the proposed technique improves the synthesized speech quality.

Full Paper

Bibliographic reference.  Kataoka, Shunsuke / Mizutani, Nobuaki / Tokuda, Keiichi / Kitamura, Tadashi (2004): "Decision-tree backing-off in HMM-based speech synthesis", In INTERSPEECH-2004, 1205-1208.