| 摘要 |
<p>The device comprises an echo cancelling circuit (3) which receives a first signal (RECEIVED) and a second signal (PM), and a real echo (ECR) between routes for producing a third signal (RESIDUE) including the second signal (PM) and a difference between the real echo and an estimated echo (ECES). Sensors (2R, 2E, 41) sense in the third signal (RESIDUE) the difference between echoes (ECR-ECES) and the second signal (PM) when the level of the third signal passes a predetermined threshold. Circuits (42, 43) gain control (GADAPT) the matching in the adaptive filtering of the echo cancelling circuit (3) in order to alter the matching gain when the second signal (PM) is not sensed and to prevent any alteration of the filtering while the second signal is being sensed. For example, for an acoustic echo in a telephone set, the echo is not processed when the third signal contains a local speech signal as the third signal.</p> |
