| 摘要 |
PROBLEM TO BE SOLVED: To automatically produce MIDI data and a music score from analog voice signals such as human singing and humming and to minimize the loss of the time resolution caused by the window interval at the time of conducting a frequency analysis. SOLUTION: The device consists of an integrating circuit 17 which integrates analog voice signals, a comparator 18 which compares the integrated output and a reference value VREF, an A/D converter 106 which converts the analog voice signals into digital signals, a DSP 105 which performs a fast Fourier transformation of the digital voice signals at a prescribed window interval and a CPU 113 which generates music score data from the power spectrum obtained by the transformation. The DSP 105 starts the windowing of the digital voice signals when the integrated output exceeds the value VREF during the comparison made by the comparator 18 and executes the fast Fourier transformation. |
