Sound separation device and sound separation method

A sound separation device comprising:

• a processor and a memory device, the processor including a signal obtainment unit, a differential signal generation unit, an acoustic signal generation unit and an extraction unit;
• the signal obtainment unit obtains a plurality of acoustic signals including a first acoustic signal and a second acoustic signal, the first acoustic signal representing a sound outputted from a first position, and the second acoustic signal representing a sound outputted from a second position;
• the differential signal generation unit generates a differential signal which is a signal representing a difference in a time domain between the first acoustic signal and the second acoustic signal;
• the acoustic signal generation unit generates, using at least one acoustic signal among the acoustic signals, a third acoustic signal including a component of a sound which is localized in a position between the first position and the second position by the sound outputted from the first position and the sound outputted from the second position;
• and
• the extraction unit generates a third frequency signal by subtracting, from a first frequency signal obtained by transforming the third acoustic signal into a frequency domain, a second frequency signal obtained by transforming the differential signal into a frequency domain, and generates a separated acoustic signal by transforming the generated third frequency signal into a time domain, the separated acoustic signal being an acoustic signal representing a sound localized in the position between the first position and the second position, the separated acoustic signal being output by the sound separation device.