The invention concerns a method (300) and system (100) for improving voice quality of a vocoder (138, 158). The method includes the steps of monitoring (312) a pitch of a voice signal (400) at a transmitting unit (110); when the pitch of the voice signal reaches a predetermined threshold (840), shifting (326) the pitch of the voice signal to at least a portion of a predetermined range (810); transmitting (338) the pitch-shifted voice signal to a receiving unit (112); and at the receiving unit, reshifting (342) the pitch-shifted voice signal to a level that compensates the step of shifting the pitch of the voice signal at the transmitting unit.