Patent ID: 8139788

Claim:
An audio signal separation apparatus for separating observation signals in the time domain of a mixture of a plurality of signals including audio signals by independent component analysis to produce isolated signals in a time-frequency domain, the apparatus comprising: a first conversion means for converting the observation signals in the time domain into observation signals in the time-frequency domain; a separation means for producing isolated signals in the time-frequency domain from the observation signals in the time-frequency domain; and a second conversion means for converting the isolated signals in the time-frequency domain into isolated signals in the time domain; the separation means being adapted to: produce isolated signals in the time-frequency domain from the observation signals in the time-frequency domain and a separation matrix substituted by initial values, compute the modified value of the separation matrix by using the isolated signals in the time-frequency domain, a score function using a multidimensional probability density function which takes a plurality of frequency components as its arguments and returning a dimensionless number as its return value, and the separation matrix, and modify the separation matrix as a function of the multidimensional probability density function until the separation matrix substantially converges by using the modified value and produce isolated signals in the time-frequency domain by using the substantially converging separation matrix.