In a digital adaptive transform coding process for transmitting and/or storing acoustic signals, in particular musical signals, scanning values N of the acoustic signals are transformed into spectral coefficients M which are divided into frequency groups, and then quantified and coded. According to the invention, the quantified maximum value of each frequency group is used to characterize the general course of the spectrum. In addition, the same bit number is allocated to all values of a frequency group and the bits are allocated to the individual frequency groups on the basis of the quantified maximum value in the respective frequency group. Also described is a multi-signal processing system, in particular for implementing the process.