| 摘要 |
In a speakerphone system, the signal that is directed to a loudspeaker is filtered by a dynamically controllable highpass filter. The filter characteristics are adjusted on the basis of the power of the signal and the degree of recent microphone activity. The filtered signal is a far-talker signal, while the microphone activity is represented as a near-talker signal that includes an echo component as a consequence of loudspeaker-to-microphone coupling. The degree of microphone activity is determined by a subband analyzer. A noise floor estimator may be used to determine the degree to which the near-talker signal is comprised of background noise, so that the noise can be eliminated in the process of controlling the highpass filter.
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