| 摘要 |
PURPOSE:To dispense with adjustment for the cutting quantity of the high frequency range component of a signal superimposed on a noise by changing the cutting quantity of the high frequency range component by the detection result of a sound volume setting position in an acoustic device and high frequency range component quantity. CONSTITUTION:When the high frequency range component level of a signal from a source medium 1 is set at a high level, a noise is not prominent by being masked by the signal. Therefore, an arithmetic part 4 applies a high control voltage to a switch 7c via a rectifier 6 to decrease the cutting quantity of a signal high frequency range component level in spite of the setting position of a sound volume 8. Also, when the high frequency range component level of the signal from the medium 11 is set at a low level and the volume 8 is set in highest sound volume, the noise is prominent, and the arithmetic part 4 applies a low control voltage to the switch 7c to increase the cutting quantity of the high frequency range component level of the signal. Adversely, when the volume 8 is set in lowest sound volume, the noise is not prominent, and the high control voltage is applied to the switch 7c to decrease the cutting quantity of the high frequency range component level. Therefore, it is possible to dispense with the adjustment for the cutting quantity of the high frequency range component. |
