FIELD: receiver of digital cellular telephone network. SUBSTANCE: device uses power approximation for detection of voice in received voice signal in noise-presence operation mode. When no voice is present, system decreases signal and outputs flat noise with filtered low frequency band. In addition, device uses set of high-pass filters for filtering received signal depending on level of background noise. Said filtering of high frequency band is used independently from presence or absence of voice component in signal. Goal of invention is achieved by combination of signal attenuation and adding flat noise with filtered lower frequency band, when no voice is detected, together with filtering higher frequency band. EFFECT: improved voice quality for decoding voice which was encoded in noise-presence operation mode. 15 cl, 6 dwg
