Abstract: Conference systems are used for example in discussions and usually comprise a plurality of delegate units with microphones, whereby in a discussion each discussion participant uses his own delegate unit. Usually the delegate units have a switch or the like, that allows the participant in front of the delegate unit to request, that his microphone is activated, so that the speech of the participant is input in the conference system and amplified by the conference system.

Abstract: Conference systems are used for example in discussions and usually comprise a plurality of delegate units with microphones, whereby in a discussion each discussion participant uses his own delegate unit. Usually the delegate units have a switch or the like, that allows the participant in front of the delegate unit to request, that his microphone is activated, so that the speech of the participant is input in the conference system and amplified by the conference system.

Abstract: Disclosed is an echo canceller comprising two or more adaptive filters for calculating echo estimates, whereby the adaptive filters each have adaptation control mechanisms for applying individual update control criteria. The adaptive filters are arranged in series. Each of the adaptation control mechanisms of the adaptive filters may apply individual update control criteria for both direct echo and diffuse echo. Several step-size reduction strategies are presented.

Abstract: An interference canceller is described, comprising an adaptive filter for modeling an interference, such as an echo or noise, and a spectral processor for processing the modeled interference together with near end speech and the interference. The interference canceller further comprises an interference model mismatch compensator coupled to the adaptive filter for providing a mismatch signal to the spectral processor, said mismatch signal showing a speech independent decay. With the model mismatch signal of the interference canceller the interference power spectrum can be estimated very accurately leading to a significant convergence improvement of the acoustic canceller. Especially in the initial convergence phase at the start of a communication session a high quality operation of the acoustic canceller is achieved, which is important as this determines the first quality impression of the user.