| 摘要 |
The subject echo canceller includes a controller, which uses a feedback arrangement to improve speech detector performance, for providing an improved multistate control signal responsive to which adjustment of the estimate is inhibited or not inhibited. For example, a first state of the control signal is provided when the value of a first function of the error signal exceeds the value of a second function of the error signal, the second function being an average of first function values. One first function may be the algebraic square of the error signal as normalized with respect to the energy detected in a far end signal, while the second function is the average of the normalized signal where the averaging is done over a predetermined time interval. The predetermined time intervals may be those time intervals during which near end speech is absent. Thus, if the value of the first function exceeds the value of the second function the first state control signal can be provided for inhibiting adjustment of the estimate. On the other hand, absent the exceeding, a second state control signal may be provided responsive to which the estimate may be adjusted.
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