In audio applications it is often necessary to process the signal in “real time”. The method of segmented wavelet transform (SegWT) makes it possible to compute the discrete-time wavelet transform of a signal segment-by-segment, not using the classical “windowing”. This means that the method could be utilized for wavelettype processing of an audio signal in real time, or alternatively in case we just need to process a long signal, but there is insufficient computational memory capacity for it (e.g. in the DSPs). In the paper, the principle of the segmented forward wavelet transform is explained and the algorithm is described in detail.