A method for determining an output stereo signal (Y 1, Y 2) based on an input stereo signal (m1, m2), the input stereo signal comprising a first input audio channel signal and a second input audio channel signal, the method comprising: determining a first differential signal (x 1) based on a difference of the first input audio channel signal (m 1) and a filtered version of the second input audio channel signal (m 2), and determining a second differential signal (x 2) based on a difference of the second input audio channel signal (m 2) and a filtered version of the first input audio channel signal (m 1); determining a first power spectrum (P 1) based on the first differential signal (x 1) and determining a second power spectrum (P 2) based on the second differential signal (x 2); determining a first weighting function (W 1) and a second weighting function (W 2) as a function of the first power spectrum (P 1) and the second power spectrum (P 2); wherein the first weighting function (W 1) and the second weighting function (W 2) comprise an exponential function; and filtering a first signal, which represents a first combination of the first input audio channel signal (m 1) and the second input audio channel signal (m 2), with the first weighting function (W 1) to obtain a first output audio channel signal (Y 1) of the output stereo signal (Y 1, Y 2), and filtering a second signal, which represents a second combination of the first input audio channel signal (m 1) and the second input audio channel signal (m 2), with the second weighting function (W 2) to obtain a second output audio channel signal (Y 2) of the output stereo signal (Y 1, Y 2); wherein the determining the first (W 1) and the second (W 2) weighting function comprises: W 1 k i = P 1 β k i P 1 β k i + P 2 β k i and W 2 k i = P 2 β k i P 1 β k i + P 2 β k i, or comprises: W 1 k i = P 1 β k i + g − 1 D β k i P 1 β k i + P 2 β k i and W 2 k i = P 2 β k i + g − 1 D β k i P 1 β k i + P 2 β k i, where P 1 (k,i) denotes the first power spectrum, P 2 (k, i) denotes the second power spectrum, W 1 (k,i) denotes the weighting function with respect to the first power spectrum, W 2 (k,i) denotes the weighting function with respect to the second power spectrum, D(k,i) is a power spectrum of a diffuse sound determined as D ( k, i) = Φ( k,i)min( P 1 ( k,i), P 2 ( k, i)), where Φ( k, i) is a normalized cross-correlation between the first and the second differential signals, g is a gain factor, β is an exponent of the exponential function, k is a time index and i is a frequency index. determining a first differential signal (x 1) based on a difference of the first input audio channel signal (m 1) and a filtered version of the second input audio channel signal (m 2), and determining a second differential signal (x 2) based on a difference of the second input audio channel signal (m 2) and a filtered version of the first input audio channel signal (m 1); determining a first power spectrum (P 1) based on the first differential signal (x 1) and determining a second power spectrum (P 2) based on the second differential signal (x 2); determining a first weighting function (W 1) and a second weighting function (W 2) as a function of the first power spectrum (P 1) and the second power spectrum (P 2); wherein the first weighting function (W 1) and the second weighting function (W 2) comprise an exponential function; and filtering a first signal, which represents a first combination of the first input audio channel signal (m 1) and the second input audio channel signal (m 2), with the first weighting function (W 1) to obtain a first output audio channel signal (Y 1) of the output stereo signal (Y 1, Y 2), and filtering a second signal, which represents a second combination of the first input audio channel signal (m 1) and the second input audio channel signal (m 2), with the second weighting function (W 2) to obtain a second output audio channel signal (Y 2) of the output stereo signal (Y 1, Y 2);