| 摘要 |
PURPOSE:To vary the sound volume delivered from the controller to secure the prescribed S/N by comparing the sound volume of the controller with the ambient external noise. CONSTITUTION:The operation of the automatic sound volume controller is indicated via control ON/OFF switch 4. Then the ratio between the ambient noise and the sound volume of the controller is set via S/N setting switch 5. These signals are stored and held in register 11. The ambient noise levels are collected through microphone 3 and then encoded through A/D converter 6 to be supplied to register 11. In the same way, the sound volume of the controller is encoded through A/D converter 12 and then supplied to register 11 from output device 1. Thus, an operation is given via processor 10 to the signals supplied to register 11 in order to secure the sound volume corresponding to the ratio set by switch 5 and thus supplied to device 1 in the form of sound volume control signal 8. |
