| 摘要 |
PURPOSE:To reproduce sound quality rich in auditory sensation by adding a high frequency component in an audible band at the time of reproducing an acoustic signal restricted in the band. CONSTITUTION:Respective high frequency component signals EH1 to EH4 to be outputted from a component wave device 2 are added to envelope detectors 11-1 to 11-4 and square circuits 8-1 to 8-4. Higher harmonic component signals from the square circuits 8-1 to 8-4 are inputted to gain control circuits 10-1 to 10-4 via BPFs 9-1 to 9-4. Respective amplitude modulation signals which was modulated in amplitude by amplitude detection signals from the envelope detectors 11-1 to 11-4 and controlled in gain via attenuators 14-1 to 14-4 are fed to an addition circuits 11. The addition circuit 11 synthsizes the respective amplitude modulation signals with a low frequency component signal from the component wave device 2 and feds the synthesized signal to a switch 15. |
