| 摘要 |
PURPOSE: To obtain a high quality decoded voice by adaptively controlling a coefficient of a high pass filter for emphasizing articulation of a decoded voice. CONSTITUTION: This device is constituted with a formant emphasizing filter 1, a high pass filter 2 of which a coefficient is variable, a power gain correcting section 3, and a filter coefficient control section 4. And the filter coefficient control section 4 calculates a rate of power of a high band for power of an input voice, and controls a filter coefficient with the value. Further, the high pass filter 2 filters an output of the formant emphasizing filter 1 using a coefficient decided by the filter coefficient control section 4, adjust smoothly variation of power of an input and an output of an adaptive post filter in the power gain correcting section 3, and makes it an output of the adaptive post filter. Thereby, articulation can be controlled without emphasizing a rasping noise and distortion of a wide band. |
