| 摘要 |
PURPOSE:To eliminate oscillation with a rasping synthetic waveform by correcting interpolation interval width so that the oscillation is prevented when the difference between a target voice parameter and a current voice parameter value is divided by the number of times of interpolation and the division result is such interpolation interval width that a synthetic voice is oscillated. CONSTITUTION:An interpolation interval width calculating means 3 is equipped with an interpolation interval width calculating circuit 31 which divides the difference between the target voice parameter value and the current parameter value by the number of times of interpolation, i.e. a frame period by an interpolation period and corrects the interpolation interval width so as to prevent the oscillation when the division result is the interpolation interval width causing the oscillation of the synthetic voice, and an interpolation interval width register 32 which holds the corrected interpolation interval width at least for a frame period. For example, this correction is made by discarding the interpolation interval width by arithmetic bit length so that the absolute value of the interpolation interval width decreases. Consequently, even when the interpolation interval width which includes an error is added to the speech parameter, the target parameter value is never exceeded, so the parameter value never approximates an adjacent parameter abnormally and the synthetic voice never oscillates. |
