4. The method according to claim 1 , further comprising: acquiring, via the processor, the voices of the plurality of unspecified speakers from a first memory storing the voices of the plurality of unspecified speakers in advance; and acquiring, via the processor, the noise from a second memory storing the noise in advance.
4. The method according to claim 1 , further comprising: acquiring, via the processor, the voices of the plurality of unspecified speakers from a first memory storing the voices of the plurality of unspecified speakers in advance; and acquiring, via the processor, the noise from a second memory storing the noise in advance. 5. The method according to claim 4 , further comprising: collecting, via the processor, noise of an environment surrounding a place where the target speaker is identified; and storing the collected noise in the second memory.