| 摘要 |
PURPOSE:To discriminate an interval of a common pitch name in each octave, by fixing the center frequency of the 1st plural band filters individually corresponding to each octave on the frequency of the interval corresponding to each block filter in each octave. CONSTITUTION:Each octave is divided into twelve intervals in accordance with twelve temperament and a signl from an acoustic signal generating circuit 1 is applied to twelve block filters F1-F12 corresponding to respective intervals. Outputs from the block filters F1-F12 are individually inputted to an interval discriminating circuit 2, which compares effective values or peak values of the outputs from the filters F1-F12 mutually and detects a signal from the filter out of the filters F1-F12 from which the maximum level is obtained. On the basis of the input signals to the circuit 2, the circuit 2 discriminates the interval to which the acoustic signal belongs and the signal indicating the interval is outputted from the circuit 2. |
