Unit Selection Cost Function Exploration Using an A* based Text-to-Speech System

International audienceSpeech synthesis systems usually use the Viterbi algorithm as a basis for unit selection, while it is not the only possible choice. In this paper, we study a speech synthesis system relying on the A* algorithm, which is a general pathfinding strategy developing a graph rather than a lattice. Using state of the art techniques, we propose and analyze different selection strategies and evaluate them using a subjective evaluation on the N-best paths returned. The best strategy achieves a MOS score of 3.29 (±0.18). More interesting, the proposed system enables an in-depth analysis of unit selection