A device for forward cancelling time-domain aliasing in a coded audio signal received in a bitstream, upon a transition from an ACELP frame to a TCX frame, comprising: a receiver for receiving the bitstream representative of the coded audio signal including FAC correction; an ACELP decoder supplied with the ACELP frame from the bitstream and including an ACELP synthesis filter, wherein the ACELP decoder produces (a) an ACELP synthesis signal and (b) a zero-input-response of the ACELP synthesis filter; means for concatenating the ACELP synthesis signal and the zero-input-response of the ACELP synthesis filter, with the ACELP synthesis signal before the zero-input response in the concatenation; an unfolded FAC window for windowing the concatenated ACELP synthesis signal and zero-input-response, wherein the unfolded FAC window comprises (a) a first half at the end of the ACELP frame for windowing the ACELP synthesis signal at the end of the ACELP frame and (b) a second half at the beginning of the TCX frame for windowing the zero-input-response at the beginning of the TCX frame following the ACELP frame; a processor (a) for folding the first half of the unfolded FAC window onto the second half of the unfolded FAC window, after windowing of the concatenated ACELP synthesis signal and zero-input-response with the unfolded FAC window, and (b) for adding the windowed and folded ACELP synthesis signal and the windowed zero-input-response; a FAC canceller comprising a FAC decoder for decoding from the received bitstream a correction signal and an inverse DCT transform for inverse DCT transforming the decoded correction signal; a TCX decoder supplied with parameters for the TCX frame from the bitstream, and an IMDCT transform and a window for the IMDCT transform for IMDCT transforming and windowing the decoded parameters to produce a TCX synthesis signal; and adder means for adding in the TCX frame (a) the added, windowed and folded ACELP synthesis signal and windowed zero-input-response, (b) the decoded and inverse DCT transformed correction signal and (c) the synthesis signal from the TCX decoder, IMDCT transform and window for the IMDCT transform to produce a FAC cancelled TCX synthesis signal for the TCX frame. a receiver for receiving the bitstream representative of the coded audio signal including FAC correction; an ACELP decoder supplied with the ACELP frame from the bitstream and including an ACELP synthesis filter, wherein the ACELP decoder produces (a) an ACELP synthesis signal and (b) a zero-input-response of the ACELP synthesis filter; means for concatenating the ACELP synthesis signal and the zero-input-response of the ACELP synthesis filter, with the ACELP synthesis signal before the zero-input response in the concatenation; an unfolded FAC window for windowing the concatenated ACELP synthesis signal and zero-input-response, wherein the unfolded FAC window comprises (a) a first half at the end of the ACELP frame for windowing the ACELP synthesis signal at the end of the ACELP frame and (b) a second half at the beginning of the TCX frame for windowing the zero-input-response at the beginning of the TCX frame following the ACELP frame; a processor (a) for folding the first half of the unfolded FAC window onto the second half of the unfolded FAC window, after windowing of the concatenated ACELP synthesis signal and zero-input-response with the unfolded FAC window, and (b) for adding the windowed and folded ACELP synthesis signal and the windowed zero-input-response; a FAC canceller comprising a FAC decoder for decoding from the received bitstream a correction signal and an inverse DCT transform for inverse DCT transforming the decoded correction signal; a TCX decoder supplied with parameters for the TCX frame from the bitstream, and an IMDCT transform and a window for the IMDCT transform for IMDCT transforming and windowing the decoded parameters to produce a TCX synthesis signal; and adder means for adding in the TCX frame (a) the added, windowed and folded ACELP synthesis signal and windowed zero-input-response, (b) the decoded and inverse DCT transformed correction signal and (c) the synthesis signal from the TCX decoder, IMDCT transform and window for the IMDCT transform to produce a FAC cancelled TCX synthesis signal for the TCX frame.