Abstract: This earphone is worn by a user and comprises: a sound pickup unit; a detection unit for detecting movement by the user or the impact of the surrounding environment; and a control unit that performs processing of output sound on the basis of a sound pickup signal picked up by the sound pickup unit and the detection result from the detection unit. For example, not only ambient sound but also noise signals such as breathing sounds, vocal sound, and pulse sounds from the user are adaptively reduced, or ambient sound is introduced into an audio signal. Alternatively, wind noise included in a voice signal or a music signal is adaptively reduced. Alternatively, the characteristics of user voice audio for transmission to be transmitted to a conversation partner terminal are adaptively adjusted, and wind noise included in the user voice audio is reduced.