A method and system receives a far-end signal and determines whether the far-end
signal is representative of a modulated signal. The method and system also receives
a near-end signal and determines whether the near-end signal is representative
of a modulated signal. Predetermined characteristics of the near and far-end signals
are determined as is whether the echo canceller will converge for the far-end signal.
The operation of the echo canceller is controlled in response to the determination
of the predetermined conditions and in response the determination of whether the
far-end and near-end signals are modulated signals.