This invention relates to a handheld-free earphone of pin contact by multi-communication devices simultaneously, especially relates to a single handheld-free earphone characterizing by containing a microprocessor, more than one output/input interfaces, a multiplex control unit, over one multiplex units, a voice processing circuit, a loudspeaker amplification and control unit, a microphone circuit, a dial unit, a charging circuit and a power supplying unit overcoming the shortcoming of receiving only one single communication pin contact of ordinary handheld ear phone. |