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.