A novel sinusoidal approach to audio signal frame loss concealment and its application in the new evs codec standard

The new 3GPP codec for Enhanced Voice Services (EVS) comprises a collection of frame loss concealment techniques, each specifically designed for the different coding modes of that codec. One of them, called “Phase Error Concealment Unit (Phase ECU)”, was developed for the High Quality (HQ) MDCT coding mode. Despite this target application, Phase ECU is a generic stand-alone tool operating on a buffer of the previously decoded and reconstructed time signal. Its framework is based on the sinusoidal analysis and synthesis paradigm. Besides a description of the basic technology we present optimizations and adaptations required for meeting the challenging 3GPP EVS codec performance requirements, and that make the method robust for a broad range of audio signals under various frame loss conditions from isolated frame erasures to severe burst loss. Test results are reported that show significant improvements over traditional techniques.