A gain control method for reducing or eliminating the undesirable effects of
acoustic
echo coupling between a speaker and a microphone while providing a full-duplex
connection. Weighted normalized far-end and near-end powers are used to first calculate
a suppression value which is used to determine the attenuation factor between an
upper and a lower limit, thus improving reliability in noisy environments. To further
improve the quality of the full-duplex connection, a smoothing factor is applied
to the attenuation calculation to provide a low power and constant sounding echo
without annoying transient-like sounds.