An acoustic echo canceller comprising an adaptive filter, a post filter,
and an adjustable filter. The adaptive filter receives a reference signal
and a near-end signal, cancels a portion of the echo in the near-end
signal using the reference signal, and provides an intermediate signal
having remaining echo not canceled by the adaptive filter. The post
filter calculates the cross-correlation between the near-end signal and
intermediate signal, and provides a set of coefficients based on a
variable suppression parameter. The adjustable filter processes the
intermediate signal based on the coefficients and provides an output
signal having at least a portion of the remaining echo removed. The
acoustic echo canceller may further comprise a channel control unit that
provides control signals, an adjustable amplifier, a noise estimator that
estimates the noise in the intermediate signal, and a noise reinsertion
unit that reinserts a version of the estimated noise back into the output
signal.