Czech Pitch Contour Modeling Using Linear Prediction

Present Czech TTS systems can produce synthetic speech with high intelligibility but low naturalness. The difference between natural and synthetic speech is still too high. Naturalness of the synthetic speech is given by the signal modeling and by the prosody modeling. This paper deals with the improving of the synthetic prosody modeling especially with the improving of the intonation modeling. A mathematical model of the pitch contour modeling can significantly limit the complexity of intonational rules creation and increase the naturalness of resulting synthetic speech. The linear prediction inonational model has been implemented into TTS system Epos for practical use. This built-in inonational model uses excitation by rules and provides in conjunction with a new triphone time domain inventories more naturalness synthetic speech than previous direct intonational rules.