A processor operates on samples of a digital output signal to determine
samples of a digital correction signal. The output signal samples are
directed to an output channel for transmission from a speaker. The
digital correction signal samples are supplied to a first
digital-to-analog converter for conversion into an analog correction
signal. The subtraction circuit generates a difference between a first
analog signal provided by a microphone and the analog correction signal.
The analog correction signal is an estimate of a contribution to the
first analog signal due to a direct path transmission between the speaker
and the microphone. The processor also receives a digital input signal
derived from the difference signal, and, performs acoustic echo
cancellation on the digital input signal to obtain a resultant signal.
The acoustic echo cancellation is configured to remove contributions to
the digital input signal due to reflected path transmissions.