| 摘要 |
<p>PRIORITY MIXER CONTROL A priority mixer control for a multi-microphone audio system which limits access of individual microphones to the system output without the imposition of a fixed entry threshold; the control comprises a threshold signal generator that develops a D.C. threshold signal starting at a maximum level for a time T1 and then decreasing in amplitude as a function of time. Each microphone channel is provided with a control channel including a comparator that compares the microphone signal, as an A.C. signal, with the threshold signal, and that switches the microphone channel to "on" condition when the microphone signal exceeds the threshold; all of the control channels are coupled to a threshold signal restoration means that drives the threshold signal back to its maximum level each time an audio channel is switched "on". An audio channel that has been switched "on" remains "on" for a time T2 substantially longer than the time T1. The number of channels currently in "on" condition is continuously monitored and the output gain is reduced whenever two or more channels are in "on" condition.</p> |
