Abstract: A method and a system for implementing echo cancellation. The method (300, 400) can include, on a first communication device (200), generating an acoustic signal (130) corresponding to an audio signal (110) received from a second communication device. Responsive to receiving a portion of the acoustic signal and detecting it is clipped, filter coefficient adaptation in an echo cancellation system (205) can be neutralized. For example, filter coefficients can be maintained at previous values, a control signal (230) that indicates zero error can be provided to an adaptive algorithm (235) that generates filter coefficients (225), a control signal can be provided that indicates to the adaptive algorithm to halt automatic updating of the filter coefficients that are generated, or a control signal can be provided that indicates to an adaptive filter (245) to halt automatic updating of the filter coefficients that are processed.

Abstract: A telephone (310) and a method for providing outbound audio when the telephone is operating in a speakerphone mode. A first data unit (350) including a first unit type identifier (360) can be received by the telephone. The first unit type identifier can be an indicator of a type of audio data contained in the first data unit. For instance, the first unit type identifier can indicate whether the audio data is music or non-music audio data. If the first unit type identifier has a first value, for example a value indicating that the audio data is music data, unmuted outbound audio reproduced from the first data unit can be provided and voice activity detection can be disabled. Additionally, inbound audio can be muted.

Abstract: The invention concerns a method (300) and system (100) for improving voice quality of a vocoder (138, 158). The method includes the steps of monitoring (312) a pitch of a voice signal (400) at a transmitting unit (110); when the pitch of the voice signal reaches a predetermined threshold (840), shifting (326) the pitch of the voice signal to at least a portion of a predetermined range (810); transmitting (338) the pitch-shifted voice signal to a receiving unit (112); and at the receiving unit, reshifting (342) the pitch-shifted voice signal to a level that compensates the step of shifting the pitch of the voice signal at the transmitting unit.