Abstract: A voice processing apparatus, comprisingan input terminal to receive electrical voice signals;a controlled-gain amplifier to amplify the electrical voice signals in dependence on a control signal to provide an output signal at an output terminal; and a control means to generate the control signal from the electrical voice signals. Wherein the control means includes: a notch filter with a passband within the range 550 to 950 Hz to produce a bandwidth reduced version of the electrical voice signals; a comparator/trigger circuit to receive the bandwidth reduced version of the electrical voice signals and to generate a trigger signal when the signal level of the bandwidth reduced version exceeds a preselected threshold; and a control signal generator to receive the trigger signal and in response thereto generate a first control signal, and in the absence of the trigger signal to generate a second control signal.