| 摘要 |
PROBLEM TO BE SOLVED: To prevent an input signal from being saturated and to prevent an acoustic signal from being distorted by correcting the input signal so as to fall in an allowable range while keeping the amplitude of the signal as it is. SOLUTION: When a signal input value at a certain sampling point is judged to be larger than the maximum input allowable value by the subtraction result by a subtracter M, the saturation of the signal input is mitigated by changing the coefficient string of impulse responses in respective delay units Z0-Z7, that is, multiplying coefficients to be multiplied to outputs of respective delay units Z0-Z7. In this case, the impulse responses with respect to the input signal become a specific characteristic curve and levels before and after that time become gradually small with respect to the input signal exceeding the maximum allowable value and then the input signal is made to be corrected so that the maximum value of the input signal becomes a value near the maximum alowable value. At this time, since the amplitude itself of the input signal is not changed and the whole of the signal is moved downward, the input signal is made to be corrected so that the whole of the signal falls in a dynamic range. |
