A side-tone control unit for a telecommunication instrument (1) is configured to include a side-tone amplifier (30) having a transfer function selectively controlled in accordance with a set of amplifier parameters, and a side-tone controller (40), coupled to the side-tone amplifier (30), for selectively applying the set of amplifier parameters to the side-tone amplifier (30) based on the detected energy of an uplink signal and the detected energy of a downlink signal. The side tone controller (40) can select a particular set of amplifier parameters by indexing a table (80) in accordance with quantized values of the detected uplink signal energy and the detected downlink signal energy.