JPS6413599A - Voice encoder - Google Patents

Abstract

PURPOSE: To make the envelope of a frame smooth and prevent a noise form being generated by controlling a pitch gain to a large fixed value when the coefficient of a pitch regenerating filter is larger than a predetermined value as to a means which makes multipulses easy to rise even in the latter half of a frame. CONSTITUTION: This encoder is equipped with a pitch extracting circuit 1 as a pitch extracting means which calculates the pitch gain of the pitch regenerating filter cascaded to a linear predictive filter based on a pitch extracted from a signal regarding an input signal and controls the calculated value to a large fixed value when the calculated value is larger than the predetermined value, and a linear predictive analyzing circuit 2 and a weighted impulse response arithmetic circuit 3 which find the impulse response of a synthesizing circuit with the pitch regenerating filter. Namely, when the pitch gain is larger than the predetermined value, the gain is controlled to the large fixed value. Consequently, the tone of an encoded voice is increased.