FIELD: recognition of stationary and non-stationary signals, in particular, for mobile radio communication. SUBSTANCE: device provides recognition of stationary and non-stationary signals, calculation of input signal power E(Ti) in several frames Ti, storing these power levels in buffer memory and using them for calculation of test variable Vt, which is equal to ratio of maximal to minimal power levels stored in buffer memory. Test variable Vt is compared to stationary state threshold γ. If it exceeds it, input signal is treated as non-stationary. EFFECT: detection and encoding and/or decoding of stationary background sounds in encoders and/or decoders of speech signals using digital frames. 15 cl, 4 dwg
