| 摘要 |
PURPOSE:To attain pleasant talking with less noise by delaying one of voice signals uttered by a driver and a passenger on the rear seat, inverting the phase by 180 deg. and superimposing the result on the other voice signal to offset electrically the sound caused by hurtling through air near the passenger. CONSTITUTION:The voice uttered by the driver is converted into an electric signal by the 1st microphone 1 at first, amplified by the 1st preamplifier 3 and the phase is delayed by a delay device 9 and the phase is inverted by 180 deg. at a phase inverting device 10. On the other hand, the voice uttered by the passenger on the rear seat is converted into an electric signal by the 2nd microphone 2, amplified by the 2nd preamplifier 4 and inputted to an adder 5 together with the voice signal of the driver as two inputs. In such an operation the sound caused by hurtling through air near the driver is offset with the sound caused by hurtling through air with delay near the passenger on the rear seat. |
