| 摘要 |
PURPOSE:To save storage capacity and to provide many PCM sounds while the storage capacity is saved by using plural sampling frequency encoded data which differ with the kinds of sounds. CONSTITUTION:Human voices 'mi' and 'si' of the Japanese syllabary are recorded in a waveform data ROM at a sampling frequency of 10KHz and other voices are recorded in a waveform data ROM 108 at a sampling frequency of 15KHz. When a key of a keyboard 112 is pressed, a CPU 104 assigns a reproduction channel for sound generation corresponding to the keying and locates the head of corresponding data in the waveform data memory 108. A corresponding channel reproduction routine reads the sound data out of the waveform data memory 108 thereafter and carries out an ADPCM(data compressed pulse code modulation) demodulating process, an integral and interpolative filtering process, a movement mean filtering process, and an amplifying process to generate channel reproduced data. Then a DAC (digital/analog converter) 114 converts the data into an analog signal and a sound system 116 regenerates its sound. |
