Audio mute for digital cordless telephone

摘要

A signal indicating the quality of the received digital data in an ADPCM cordless telephone system is monitored and a transition from good to poor quality is detected. In response to this detection, a first attenuation level is applied to the received signal, the level being selected to maintain the intelligibility of the signal to the user while lowering the volume thereof. The first attenuation level is then reduced such that reduced attenuation is maintained over a time interval selected to accommodate for the known error propagation time of the ADPCM signal. An optional clipping circuit may be employed to limit the excursion of the output audio signal.