| 摘要 |
PURPOSE:To simplify the constitution, by providing a digital filter having a strong resonance characteristic for a post-stage of another digital filter having a certain resonance characteristic and making a connection so as to reduce the gain of the two digital filters to a value smaller than a prescribed value. CONSTITUTION:A voice coder 1 starts a control circuit 3 according to an instruction inputted from an outputted instruction input terminal 2 and initiates the synthesizing processing. The control circuit 3 performs the address designation of a coefficient of filter inputted to digital filters 6-9 and the address designation of sound source information inputted to a sound source generating circuit 4 to a synthesized information storage circuit 5. In the synthesized information storage circuit 5, when the digital filters 6-9 have inputs, the gain by the filters 6, 7 and 8, 9 is smaller than a prescribed value and the filter coefficients having the strong resonance characteristics are stored in order at the post-stage of the filter coefficients having the weak resonance characteristics. Further, in the control circuit 3, the strength of the resonance characteristics of the two digital filters and the gain in case of cascade connection are detected, and the inputted address of the filter coefficients is changed, allowing to obtain an effect equivalent to that of a conventional scaler. |
