Parameter Generation Considering LSP Ordering Property for HMM-Based Speech Synthesis

The ordering property of LSP cannot be guaranteed during HMM-based speech synthesis when LSP is adopted as the spectrum feature, with the result that naturalness of synthetic speech will degrade. This letter introduces a modified parameter generation method to preserve ordering property of generated LSPs, by not only maximizing the likelihoods of HMM and global variance (GV) as in conventional method but also minizing a penalty on mis-orderings. Experimental results show that the proposed method can alleviate the mis-orderings significantly and achieve high quality synthesizing performance when the penalty weight is selected appropriately.