When several signals (k1, k2) that are not independent from each other are coded, the appropriate type of coding is selected depending on a similarity measurement. In one aspect of the invention, the similarity measurement is determined by one of the signals (k1, k2) being at first coded according to the intensity stereo process and then decoded, in order to create a signal (ki1, ki2) affected by a coding error. Said signal and the corresponding non-coded signal are then transformed into the frequency range. The actually audible spectral components of both the signals (ki1, ki2) affected by a coding error and the corresponding signal (k1, k2) unaffected by a coding error are selected or evaluated in the frequency range by using a listening threshold determined by a psychoacoustic calculation. When the degree of similarity is high, an intensity stereo coding process is carried out, otherwise the channels are separately coded.