1. A method for synthesizing a speech, comprising: dividing a phoneme sequence corresponding to a target speech into a plurality of segments; selecting a plurality of speech units for each segment from a speech unit memory storing speech units having at least one frame, the plurality of speech units having a prosodic feature accordant or similar to the target speech; generating a formant parameter having at least one formant frequency for each frame of the plurality of speech units; corresponding the formant frequencies of the formant parameters among corresponding frames of the plurality of speech units; generating a fused formant parameter of each frame from corresponded formant frequencies of formant parameters of each frame of the plurality of speech units; generating a fused speech unit of each segment from the fused formant parameter of each frame; and generating a synthesized speech by concatenating the fused speech unit of each segment.
1. A method for synthesizing a speech, comprising: dividing a phoneme sequence corresponding to a target speech into a plurality of segments; selecting a plurality of speech units for each segment from a speech unit memory storing speech units having at least one frame, the plurality of speech units having a prosodic feature accordant or similar to the target speech; generating a formant parameter having at least one formant frequency for each frame of the plurality of speech units; corresponding the formant frequencies of the formant parameters among corresponding frames of the plurality of speech units; generating a fused formant parameter of each frame from corresponded formant frequencies of formant parameters of each frame of the plurality of speech units; generating a fused speech unit of each segment from the fused formant parameter of each frame; and generating a synthesized speech by concatenating the fused speech unit of each segment. 2. The method according to claim 1 , wherein generating a formant parameter comprises extracting a formant parameter of each of the plurality of speech units from a formant parameter memory storing formant parameters each corresponding to a speech unit.