A method of encoding an audio signal, the method comprising: segmenting the audio signal into a plurality of frames, wherein each of the frames includes M samples and M is a natural number greater than one; applying a first window, a second window, and at least one third window to the frames, wherein: a first window and at least one third window are applied, in case of a first transient signal duration, t1, whereby the first window and the at least one third window overlap in the first transient signal duration, t1, wherein a length of the second window is longer than a length of the first window, and a length of the at least one third window is longer than the length of the first window and shorter than the length of the second window; and two third windows (53-2, 53-3) are applied, in case of a second transient signal duration, t2, shorter than the first transient signal duration, t1, whereby the two third windows overlap in the second transient signal duration, t2, and wherein a sum of lengths of the two third windows is the same as a length of the second window, time-frequency transforming the frames to which the first window, the second window, and the at least one third window have been applied; and generating a bitstream including the time-frequency transformed frames; and wherein each of the second window and the at least one third window includes a first zero duration and a second zero duration, in which a coefficient is zero, and a unity duration, in which a coefficient is one, and a length of the first zero duration, the second zero duration, and the unity duration is determined to satisfy a perfect reconstruction condition. segmenting the audio signal into a plurality of frames, wherein each of the frames includes M samples and M is a natural number greater than one; applying a first window, a second window, and at least one third window to the frames, wherein: a first window and at least one third window are applied, in case of a first transient signal duration, t1, whereby the first window and the at least one third window overlap in the first transient signal duration, t1, wherein a length of the second window is longer than a length of the first window, and a length of the at least one third window is longer than the length of the first window and shorter than the length of the second window; and two third windows (53-2, 53-3) are applied, in case of a second transient signal duration, t2, shorter than the first transient signal duration, t1, whereby the two third windows overlap in the second transient signal duration, t2, and wherein a sum of lengths of the two third windows is the same as a length of the second window, time-frequency transforming the frames to which the first window, the second window, and the at least one third window have been applied; and a first window and at least one third window are applied, in case of a first transient signal duration, t1, whereby the first window and the at least one third window overlap in the first transient signal duration, t1, wherein a length of the second window is longer than a length of the first window, and a length of the at least one third window is longer than the length of the first window and shorter than the length of the second window; and two third windows (53-2, 53-3) are applied, in case of a second transient signal duration, t2, shorter than the first transient signal duration, t1, whereby the two third windows overlap in the second transient signal duration, t2, and wherein a sum of lengths of the two third windows is the same as a length of the second window, time-frequency transforming the frames to which the first window, the second window, and the at least one third window have been applied; and generating a bitstream including the time-frequency transformed frames; and wherein each of the second window and the at least one third window includes a first zero duration and a second zero duration, in which a coefficient is zero, and a unity duration, in which a coefficient is one, and a length of the first zero duration, the second zero duration, and the unity duration is determined to satisfy a perfect reconstruction condition.