We proposed an algorithm which enables to detect the number of speakers, accurate s and spectral envelopes from co-channel input simultaneous speech signals with spectral domain procedure. It showed a high performance for speech signals of both single speaker and two speakers. Still, several improvements are prospective by considering temporal continuity of contour (e.g., introducing Fujisaki model), incorporating variance into the model parameters also as a variable or by introducing a priori probability distribution of the model parameters, etc.