Provided is an information processor including a signal processing section that acquires a first signal to be detected by an acoustic input section of a first unit including the acoustic input section disposed within a predetermined distance from one ear hole of a user in a state of being worn by the user, acquires a second signal, which indicates a noise generated from a noise source, to be acquired by a second unit, and generates a noise cancellation signal directed to the noise on the basis of the first signal and the second signal.