Abstract: A method of improving convergence of an echo canceller in a full duplex speakerphone, wherein the echo canceller includes LEC (Line Echo Canceller) and AEC (Acoustic Echo Canceller) portions, comprising the steps of capturing LEC coefficients during operation, storing the coefficients, and utilizing the stored coefficients as default values during start-up of a subsequent call. The method of the present invention reduces the overall convergence time of the echo canceller by alleviating the requirement to wait for a suitable reference signal in order to converge the LEC.

Abstract: In a device having a sound source within an enclosure and a first microphone for picking up sounds outside the enclosure, a system for improving acoustic separation between the sound source and first microphone comprising an additional microphone located approximately equidistant from the sound as the first microphone for picking up sounds within the enclosure, and a circuit connected to the first microphone and the additional microphone for subtracting the sounds within the enclosure from the sounds outside the enclosure.

Abstract: A printed circuit assembly comprises a first printed circuit (5) having conductive (4) paths formed on a top surface (27) thereof and a second printed circuit (1) having conductive paths (2) formed on a top surface thereof. The first printed overlies the second circuit in a staggered relationship so that an edge thereof lies on the top surface of the second printed circuit. The second printed circuit has a portion protruding beyond this edge. A first set of contact members (13) is formed on the first printed circuit adjacent its edge. A second set of corresponding contact members (14) is formed on the protruding portion of the second printed circuit in opposing relationship to the first set of contact members. A sheet member is fitted over the printed circuits and carries bridging members for establishing electrical contact between corresponding pairs of contact members.