Patent ID: 7912211

Claim:
A portable full-duplex audio product, comprising: an enclosure; a full-duplex data port located to said enclosure operable to transmit to and receive from a far-side participant audio data; a microphone located to said enclosure; a speaker located to said enclosure; a microphone input adapted to receive audio data from a microphone; a speaker output adapted to provide audio data received from said data port to a sound producing device; a far-side frequency decomposer operable to decompose the far-side audio data received from said data port; a microphone frequency decomposer operable to decompose the audio data received at said microphone input into a number of frequency bands; an echo canceller receiving audio data originating at said microphone input and said data port, said echo canceller including echo cancellation coefficients, wherein said echo canceller is operable to convolve said echo cancellation coefficients with the data received at said data port to generate an echo cancellation signal, further wherein said echo canceller applies the echo cancellation signal to the data received at said microphone input; an echo cancellation coefficients converger operable to converge said echo cancellation coefficients to a solution corresponding to the accumulation of the echo paths in the physical environment between the sound producers producing sound from said speaker output and the sound receivers for which said microphone input is receiving, said converger being further controllable such that at certain times adaptation of said echo cancellation coefficients proceeds and at other times adaptation is prevented; a doubletalk detector receiving low-frequency audio information from said far-side frequency decomposer and said microphone frequency decomposer, said doubletalk detector controlling the proceeding of whether said echo cancellation coefficients converger is adapting said echo cancellation coefficients, said doubletalk detector determining doubletalk by a comparison of low-frequency audio signal levels received from said decomposers.