An audio system is provided that comprises a headphone for reading music information or the like recorded in a memory card attached to an external interface to reproduce audio signal and for outputting sound conforming to the audio signal; and a remote control unit for transmitting control signal for controlling reproduction function or the like of the music information of the headphone to the headphone due to infrared rays. In the audio system, the control signal of infrared rays of less data amount compared with the audio signal or the like is transmitted. Accordingly, circuit configuration and component configuration can be made simpler, the remote control unit can be downsized, and the headphone and the remote control unit can be made wireless, resulting in an easier handling.