Novel adaptive muting technique for packet loss concealment of ITU-T G.722 using optimized parametric shaping functions

Adaptive muting method using an optimized parametric shaping function as a part of the ITU-T G.722 Appendix IV packet loss concealment algorithm is proposed. The packet loss concealment algorithm incorporating an adaptive muting scheme is known to prevent the generation of unpleasant sounds during packet loss concealment. However, original muting uses a piece-wise linear muting curve according to packet errors so that our muting approach uses non-linear parametric shaping functions including sigmoid and raised-cosine. Training is substantially performed to determine the parameters of the two shaping functions in terms of objective speech quality measures, and optimal parameters are finally selected by subjective speech quality. Through extensive experiments, this proposed muting technique turns out to improve the performance of the reference muting mechanisms in the packet loss concealment algorithm of the G.722 Appendix IV under various experimental conditions.