| 摘要 |
PURPOSE:To give the signal pleasantly and with safety to the driver, by decreasing the masking of noise through automatic adjustment of the level and characteristics of signal reproduction in listening, depending on the noise level at running. CONSTITUTION:The in-house noise 1 due to car running is picked up with the microphone 2 and the signal tone to be listened is added, but most part of the signal tone is cut off at the low pass filter 3. The output 4 of the filter 3 is the signal 6 showing effective value through the square detector 5. The signal to be listened is directly fed to the switch 14 from the reproduction unit 7 such as tape deck and tuner through the switch 8 of the signal transmission line A via the switch 14 or switch 8 and equalizer 11 for masking compensation and gain adjuster 12. When the running noise level detected is compared with the switching level preset at the switches 8, 14, and the signal 6 performs this switching and gain adjustment is made to the adjuster 12 according to the noise level. Accordingly, the driver can enjoy the listening signal pleasantly and safely. |
