Method and apparatus for synthesizing speech

摘要

A speech synthesizing method and apparatus arranged to use a sinusoidal waveform synthesis technique provide for preventing degradation of acoustic quality caused by the shift of the phase when synthesizing a sinusoidal waveform. A decoding unit decodes the data from an encoding side. The decoded data is transformed into the voiced/unvoiced data through a bad frame mask unit. Then, an unvoiced frame detecting circuit detects an unvoiced frame from the data. If there exist two or more continuous unvoiced frames, a voiced sound synthesizing unit initializes the phases of a fundamental wave and its harmonic into a given value such as 0 or pi /2. This makes it possible to initialize the phase shift between the unvoiced and the voiced frames at a start point of the voiced frame, thereby preventing degradation of acoustic quality such as distortion of a synthesized sound caused by dephasing.