| 摘要 |
A speech-controlled bidirectional amplifier that includes first and second transmission channels each with a control member controlled by speech signals derived at control points preceding the control member. First and second comparison devices responsive to the levels of the speech signals control a third comparison device that in turn controls the attenuation level of the control members. The amplifier is arranged so that in the rest condition both control members provide a high signal attenuation. When speech signals are transmitted through one channel, the other channel is cut-off. However, an interrupt facility is provided whereby a speech signal above a given level in the cut-off channel will cause the apparatus to switch over so that the cut-off channel is opened and the previously open channel is then cut-off. |
