In order to compensate tonal changes arising from a multi-path propagation of sound portions during the mixing of multi microphone audio recordings as far as possible it is suggested to form spectral values of respectively overlapping time frames of samples of each a first microphone signal (100) and a second microphone signal (101). The spectral values (300) of the first microphone signal (100) are distributed with formation of spectral values (311) of a first sum signal to the spectral values (301) of a second microphone signal (101) in a first summing level (310), whereat a dynamic correction of the spectral values (300, 301) of one of the two microphone signals (100, 101) occurs. Spectral values (399) of a result signal are formed out of the spectral values (311) of the first sum signal which are subject to an inverse Fourier-transformation and a block junction (FIG. 3).