| 摘要 |
<p>PURPOSE:To prevent the generation of a howling phenomenon by automatically measuring the mixing direction of an acoustic signal from a speaker to a microphone and automatically setting the dead angle of the microphone. CONSTITUTION:The sound collection of a first voice, for example, is executed by a microphone 1 for sound collection, this signal amplifies up to a level necessary for an amplification circuit 2 through a directional control circuit 4 and an adding circuit 5 and is loud-spoken by a speaker 3. A second signal to detect the direction of the speaker 3 to be seen from the microphone 1 for the sound collection is superimposed over the entire frequency band at a low level not to disturb the loud-speaking signal in this loud-speaking signal. The signal is received by a microphone 6 for a directional detection, detected, the direction of the speaker 3 is detected, the directional control of the microphone 1 for the sound collection is executed according to the result and the dead angle of the microphone 1 is exactly turned to the speaker 3. Thus, the howling can be controlled.</p> |
