Abstract: The invention relates to a method of forming one or more digital audio mixed signals (Sout) on the basis of at least two digital audio source signals (S1, S2), in which the digital audio mixed signal or signals are formed by mixing the digital audio source signals. A characteristic digital magnitude of at least one digital audio source signal is compressed into a series of bits and said series of bits is inserted into said digital audio source signal or into the digital audio mixed signals in an almost inaudible or inaudible manner, The characteristic digital magnitude is the temporal, spectral or spectro-temporal distribution of said digital audio source signal or the temporal, spectral or spectro-temporal contribution of said digital audio source signal in the mixed signal or signals, or said digital audio source signal.