Abstract: Source separation system for processing input signals (E.sub.i (t)) formed by instantaneous linear mixtures of primary signals (X.sub.j (t)) that result from sources (S1-Sn) and for producing at least one estimated primary signal (x.sub.k (t)) . The system includes separation apparatus (10) and characterization apparatus (15) which determine cumulants of the input signals for extracting estimated mixing coefficients (.alpha..sub.ij). The coefficients are transformed into separation coefficients (C.sub.ki, d.sub.ki) in the separation apparatus (10). The separation apparatus (10) may have a direct structure or a recursive structure.