| 摘要 |
<p>A portable audio playback device is a device that uses an earphone to play an audio signal, and is provided with a device body, a general-user earphone and a hearing-impaired-user earphone. A jack (90) in the device body connects to either the general-user earphone or the hearing-impaired-user earphone. A dummy terminal (23C) effectively insulated from other terminals is provided on a connection plug (23) of the hearing-impaired-user earphone (20). When a general-user earphone connection plug or the hearing-impaired-user earphone connection plug is inserted in the jack (90), an audio playback circuit in the device body switches to an audio amplification mode for the audio signal, on the basis of detection of the existence of the dummy terminal (23C).</p> |
