| 摘要 |
PURPOSE:To reduce click noise leaked to a receiving side of a conference telephone system, by connecting an integrator between a level detector and a light emitting display and making the change in current flowing to the light emitting display gentle with the change in an input current of the integrator. CONSTITUTION:A voice signal inputted to microphones 1<1>-1<n> is amplified at amplifiers 2<1>-2<n>, transmitted to a receiving side via a mixing circut 6, its amplified signal is detected at level detectors 3<1>-3<n> and light emitting diodes 5<1>-5<n> are lighted when the level reaches a prescribed level or over. Further, integrators 4<1>-4<n> are connected between the level detectors 3<1>-3<n> and the light emitting diodes 5<1>-5<n> so as to make the current change flowing at the flickering of the light emitting diodes 5<1>-5<n> gentle. |
