| 摘要 |
PURPOSE:To attain simple and inexpensive circuit constitution and less power consumption by applying rough correction with a 1st filter section of IIR filter constitution of a digital filter section and applying filter correction with a 2nd filter section of FIR filter constitution. CONSTITUTION:A digital filter section 20 consists of 2-stage of filter sections comprising a 1st filter section 21 of IIR filter constitution and a 2nd filter section 22 of FIR filter constitution. Rough correction is applied by the 1st filter section 21 and detailed correction is applied by the 2nd filter section 22 to attain correction for a sound signal with high accuracy. Then the 1st filter section 21 has a few number of divided frequency bands and is provided with IIR filters with a few number in comparison with the correction with the IIR filter only and since the frequency band for filter correction is limited by an output signal of the 1st filter section 21, the 2nd filter section 22 is formed by providing the FIR filter with comparatively simple constitution. Thus, the circuit constitution is simple and inexpensive, furthermore, the power consumption is less. |
