| 摘要 |
Computer Controlled Speakerphone for Adapting to a Communication Line A computer controlled speakerphone includes a line adapting arrangement for developing information about an interface between the speakerphone and a hybrid in a communication line and for providing optimal performance during operation by adapting operating parameters of the speakerphone to the line. During a conversation, the line adapting arrangement measures and averages the degree of hybrid reflection that is presented to the speakerphone. The hybrid reflection provides a measure of both the hybrid and a far-end acoustic return. By determining the degree of hybrid reflection, the switching threshold level of the speakerphone for switching between the transmit and the receive state may be adjusted. Once the expected level of receive speech due to hybrid reflection is known, additional receive speech due to the far-end talker may be accurately determined and the state of the speakerphone switched accordingly. The amount of switched loss required in the transmit and receive speech paths of the speakerphone to maintain stability may be also be adjusted by the line adapting arrangement in accordance with the degree of hybrid reflection. By lowering the amount of switched loss, speakerphone switching operation becomes more transparent and can even approach full-duplex for fully digital connections.
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