| 摘要 |
PURPOSE:To smoothly switch an image signal by suitably detecting a voice signal at a maximum voice level. CONSTITUTION:A reference voice generating part 23-1 generates a reference voice at a fixed frequency and a fixed level under the control of a reference voice generation control part 22-1. The reference voice is transmitted through a microphone 24-1, microphone amplifier 25-1, video conference terminal 21-1 and line to a multi-spot video conference controller 1. At the multi-spot video conference controller 1, a voice signal gain correcting circuit 141 detects the reference voice from a voice signal inputted through a line interface part 11-1, MUX/DMUX 12-1 and voice decoding part 13-1 and calculates the amount of gain attenuation so that the level of the voice signal of the detected reference voice can be a reference level set in advance. |
