According to the invention a receiving end terminal (RET) enters a delay mode based on the detecting of the quality of the link being lower than a threshold. In this delay mode, the receiving end terminal provides a reception delay indicator (RDI) for a sending end terminal (SET). The sending end terminal (SET) receives the reception delay indicator (RDI) and provides an end of speech indicator (ESI) for the receiving end terminal (RET) at an end of a speech coding interval (SC). The receiving end terminal (RET) uses the reception delay indicator (RDI) and end of speech indicator (ESI) to define a first time interval (AL1) during which a speech decoder is disabled. The speech decoder is again activated after the first time interval (AL1).