Patent ID: 8818001

Claim:
A signal processing apparatus comprising: a separation processing unit that generates observed signals in the time frequency domain by performing the short-time Fourier transform (STFT) on mixed signals as outputs, which are acquired from a plurality of sound sources by a plurality of sensors, and generates sound source separation results corresponding to the sound sources by performing a linear filtering process on the observed signals, wherein the separation processing unit has a linear filtering process section that performs the linear filtering process on the observed signals so as to generate separated signals corresponding to the respective sound sources, an all-null spatial filtering section that applies all-null spatial filters which form null beams toward all the sound sources included in the observed signals acquired by the plurality of sensors so as to generate signals filtered with the all-null spatial filters (spatially filtered signals) in which the acquired sounds in null directions are removed, and a frequency filtering section that performs a filtering process of removing signal components corresponding to the spatially filtered signals included in the separated signals by inputting the separated signals and the spatially filtered signals, wherein the frequency filtering section performs a process of changing a level of removal of components corresponding to the spatially filtered signals from the separated signals in accordance with a channel of the separated signals, thereby generating processing results of the frequency filtering section as the sound source separation results.