Electronic accessory apparatus and audible signal transmission method thereof

An electronic accessory apparatus, comprising:

• a type C universal serial bus connector, having a plurality of data pin sets, a first ground pin and a second ground pin;
• a first switch circuit, coupled to a first selected data pin set among the data pin sets, and transmitting a data signal set or an audio output signal set to the first selected data pin set according to a first control signal;
• a second switch circuit, coupled to the first selected data pin set, and transmitting the audio output signal set to the first selected data pin set according to the first control signal;
• a grounding switch circuit, coupled between the first ground pin, the second ground pin and a reference ground, and being turned on or cut off according to a second control signal;
• and
• a first channel selector, coupled to the first ground pin and the second ground pin, and setting a signal transmission relation between a first audio input signal set, the first ground pin and the second ground pin.