The invention proposes a digital signal coding method including a step (E1) of analysing the digital signal (IM) into a plurality of frequency sub-bands, at least one first sub-band having a lower frequency and at least one second sub-band having a higher frequency, characterised in that it includes, for each second sub-band, the steps of: dividing (E4) the second sub-bands into blocks (B.sub.p,n), selecting (E9) first blocks which are to be coded by setting to a predetermined value and second blocks which are to be coded by trellis coded quantization, according to a selection criterion, linking (E16) the second blocks selected at the previous step in order to form a series of blocks, coding (E17) the series of blocks by trellis coded quantization of a series of coefficients extracted from the second blocks of the second sub-band.