A computer-implemented method comprising: processing a bit stream for an audio signal, including, if one or more missing frames is encountered while processing the bit stream, selecting a concealment technique from among multiple available signal-dependent concealment techniques based on a classification of an available frame prior to the one or more missing frames and a classification of an available generating the frame following the one or more missing frames in the audio signal, and a count of the one or more missing frames, the count indicating how many consecutive frames are missing, wherein the classification of the available prior frame is one of a set of possible classifications comprising voiced and unvoiced; performing the selected concealment technique; and outputting a result; wherein, if the classification of the available prior frame is voiced, then the selected concealment technique comprises using a pitch extension technique to generate a concealment signal; if the classification of the available prior frame is unvoiced, then the selected concealment technique comprises generating the concealment signal based at least in part on energy of the available prior frame; if the classification of the available prior frame and the classification of the available frame following the one or more missing frames in the audio signal are both voiced, and the count of the one or more missing frames is less than a threshold value, then the selected concealment technique comprises bi-directional concealment; and if the classification of the available prior frame is voiced, and the count of the one or more missing frames is more than a threshold value, then the selected concealment technique comprises unidirectional concealment. processing a bit stream for an audio signal, including, if one or more missing frames is encountered while processing the bit stream, selecting a concealment technique from among multiple available signal-dependent concealment techniques based on a classification of an available frame prior to the one or more missing frames and a classification of an available generating the frame following the one or more missing frames in the audio signal, and a count of the one or more missing frames, the count indicating how many consecutive frames are missing, wherein the classification of the available prior frame is one of a set of possible classifications comprising voiced and unvoiced; performing the selected concealment technique; and outputting a result; if the classification of the available prior frame is voiced, then the selected concealment technique comprises using a pitch extension technique to generate a concealment signal; if the classification of the available prior frame is unvoiced, then the selected concealment technique comprises generating the concealment signal based at least in part on energy of the available prior frame; if the classification of the available prior frame and the classification of the available frame following the one or more missing frames in the audio signal are both voiced, and the count of the one or more missing frames is less than a threshold value, then the selected concealment technique comprises bi-directional concealment; and if the classification of the available prior frame is voiced, and the count of the one or more missing frames is more than a threshold value, then the selected concealment technique comprises unidirectional concealment.