Conferencing system adaptive signal conditioner

摘要

The disclosed arrangement of digital signal processor and echo cancellor is connectable to four wire transmission facilities on a per port basis for providing adaptive signal conditioning to reduce noise and improve level contrast among conferees of a digital conference connection. The digital signal processor applies an adaptive gain value to incoming speech signals for either increasing or decreasing the level of these signals to meet a predetermined threshold. A fixed gain adjustment is applied to incoming noise signals to reduce the level of these signals. The arrangement also provides a last-talker holdover mode in which the last gain adjustment applied to last-talker speech is applied to idle channel noise on that line.