1. A method for decoding audio frames, the method comprising the steps of: decoding a first audio frame with a first decoder to produce a first reconstructed audio signal: determining a filter state for a second decoder from the first reconstructed audio signal, wherein determining the filter state for the second decoder comprises determining an inverse of the filter state that is initialized in the second decoder; back-propagating the first reconstructed audio signal to the second decoder via the inverse of the filter corresponding to the second decoder; transferring the determined filter state to the filter corresponding to the second decoder; initializing the second decoder with the filter state determined from the first reconstructed audio signal; and decoding speech frames with the second decoder initialized with the filter state wherein: the step of determining the filter state comprises performing at least one of down sampling of the reconstructed audio signal and pre-emphasis of the reconstructed audio signal; and the step of initializing the second decoder with the filter state is accomplished by receiving at least one of an upsampling filter state and a de-emphasis filter state.