Set-top box, earphones and video broadcast method

The invention provides a set-top box which comprises a content receiving module, a playing module, a communication module and an audio transmission module. The content receiving module receives a video program from a head end. The video program comprises at least one set of video contents and a plurality of sets of corresponding audio contents, and each audio content corresponds to a mark number. The playing module sends the video contents and one set of audio contents to a video playing device to play. The communication module sends the corresponding mark numbers of a plurality of sets of audio contents to each pair of earphones, and receives the only identifier and the mark number of the audio content to be played from the earphones. The invention also provides the earphones and a video playing method. According to the invention, the audio contents in a plurality of languages can be played while the same video content is played.