11 Adaptive Multi-Rate Wideband speech codec error concealment of lost frames

26.1713GPPAdaptive Multi-Rate - Wideband (AMR-WB) speech codecGeneral descriptionSpeech codec speech processing functionsTS

The adaptive multi-rate wideband speech codec error concealment of erroneous or lost frames is described in [8].

Frames may be erroneous due to transmission errors or frames may be lost due to frame stealing in a wireless environment or packet loss in a transport network.. The methods described in [8] may be used as a basis for error concealment.

In order to mask the effect of isolated erroneous/lost frames, the speech decoder shall be informed about erroneous/lost frames and the error concealment actions shall be initiated, whereby a set of predicted parameters are used in the speech synthesis. Insertion of speech signal independent silence frames is not allowed. For several subsequent erroneous/lost frames, a muting technique shall be used to indicate to the listener that transmission has been interrupted.