**5.2 Emotional speech synthesis**

Speech is the easiest way to convey intention, and it is one of the fundamental methods of conveying emotion, on a par with facial expression. In this paper, the variety rule of prosodic features containing pitch frequency (F0), energy and velocity are concluded by analyzing emotional speech in our Emotional Speech Database. The autocorrelation function (ACF) method based on Linear Predictive Coding (LPC) and wavelet transform approach are employed to extract the F0 and tone respectively. Then prosodic features regulation is set up by utilization of Pitch Synchronous OverLap Add (PSOLA) and the original peace speeches are transformed into appointed emotional speech, including happy, anger, surprise and sad, based on the rules and regulation. Figure 8 illustrates the work flow of our approach.

Fig. 8. Work flow of the emotional speech synthesis.

