Synthesized speech can be largely degraded in noise, resulting in compromised speech quality. In this paper, we propose a unit selection based speech synthesis system for better speech quality under poor channel conditions. First, the measurement of speech intelligibility is incorporated in the cost function as a searching criterion for unit selection. Next, the prosody of the selected units is modified according to the Lombard effect. Prosody modification includes increasing the amplitude of unvoiced phoneme and enlarging the speech duration. Finally, the FIR equalization via convex optimization is applied to reduce signal distortion due to the channel effect. Listening test in our experiments shows that the quality level of synthetic speech can be improved under poor channel conditions with the help of our proposed synthesis system.
Bibliographic reference. Cen, Ling / Dong, Minghui / Chan, Paul / Li, Haizhou (2009): "Unit selection based speech synthesis for poor channel condition", In INTERSPEECH-2009, 2075-2078.