Blind voice separation refers to retrieve a set of independent sources combined
by an unknown destructive system. The proposed separation procedure is based on
processing of the observed sources without having any information about the combinational
model or statistics of the source signals. Also, the number of combined sources is usually
predefined and it is difficult to estimate based on the combined sources. In this paper, a new
algorithm is introduced to resolve these issues using empirical mode decomposition
technique as a pre-processing step. The proposed method can determine precisely the
number of mixed voice signals based on the energy and kurtosis criteria of the captured
intrinsic mode functions. Also, the separation procedure employs a grey wolf optimization
algorithm with a new cost function in the optimization procedure. The experimental results
show that the proposed separation algorithm performs prominently better than the earlier
methods in this context. Moreover, the simulation results in the presence of white noise
emphasize the proper performance of the presented method and the prominent role of the
presented cost function especially when the number of sources is high.