Patent ID: 6542611
Filing Date: 2003-04-01
Classification: H04B

Abstract:
A method of suppressing echo of a locally originating audio signal from a return transmission audio signal, the method comprising the steps of:detecting voice activity in the locally originating audio signal; processing the locally originating audio signal and return transmission audio signal according to a multi-state operating sequence having at least one correlate state during which the processing correlates the locally originating audio signal to echo in the return transmission audio signal, and an echo suppress state in which the processing suppresses echo in the return transmission audio signal to produce an echo suppressed audio signal; selectively switching among at least the locally originating audio signal and the echo suppressed audio signal for output to a monitoring device depending on a current state in the multi-state operating sequence; causing a transition to a first of the at least one correlate state in response to the presence of voice activity in the locally originating audio signal being detected; and switching to output of the locally originating audio signal in the first of the at least one correlate state.