Abstract: A digital filter bank (10) which has a discrete cosine transform section (12) and a polyphase network section (14) has the polyphase network section configured with a plurality of single input-double output digital filters (16). The filters have one of their outputs (36) independent of their present input signal. This permits a single multiplier-accumulator to use a "memory swapping" procedure to accumulate all the requisite information from a complementary pair of the filters and to perform the necessary operations on it to compute an output value, while clearing the accumulator only once each sampling period.