Delay-less frequency domain packet-loss concealment for tonal audio signals

A delay-less packet-loss concealment (PLC) method for stationary tonal signals is presented, that addresses audio codecs utilizing a modified discrete cosine transformation (MDCT). In the case of a frame loss, tonal components are detected using the last two received spectra and their accompanied pitch information. Phases of the tonal components are subsequently predicted, aiming for a continuous phase evolution between successive frames. Thus, accurate estimates of tonal components are achieved for stationary signals during frame losses, leading to an improved listening impression. This method is used in the recently standardized enhanced voice services (EVS) codec. Subjective quality evaluation using a MUSHRA test demonstrates its performance.