The present invention enable to separate source signals from mixture signals
into which the source signals are mixed temporally and spatially, where the number
of source signals is more than or equal to the number of mixture signals. A signal
storing portion 12 stores the mixture signals input into a signal input
portion 11, and a formulation portion 131 in a signal separation
portion 13 extracts the mixture signals stored in the signal storing portion
12 and formulates them as an operation expression using a basis matrix composed
of plural small matrixes that consist of bases with time symmetry. A learning algorithm
application portion 132 applies a learning algorithm based on overcomplete
representations, a mixture matrix calculating portion 133 calculates a mixture
matrix, a source signal estimating portion 134 estimates source signals
separated from the mixture signals, and an output portion 14 outputs the
calculated mixture matrix and the estimated source signals.