“…In the end, the final separated signals are identified by the cross-correlations values, which means that the lower the values of the cross-correlations of the separated signals are, the more mutual independence they have. In order to verify the effectiveness of our algorithm, six swarm intelligence algorithms (PSO [ 3 , 24 ], GA [ 25 , 26 ], DE [ 27 , 28 , 29 ], SCA [ 30 , 31 , 32 ], BOA [ 33 , 34 ], and CSA [ 35 , 36 ]) are applied. The results of separation were compared in terms of separation performance, separation success rate, and applicability according to the cross-correlation and three kinds of separation evaluation indexes (scale invariant signal-to-distortion ratio (SI-SDR), perceptual evaluation of speech quality (PESQ), and short-time objective intelligibility (STOI) [ 37 , 38 , 39 , 40 ]).…”