An electronic device comprises a first output module, a judgment module, a first switch module, a second output module, an operation module, a second switch module and a play module. The first output module generates a first audio signal. The second output module generates second audio signals. If the first audio signal is generated, the judgment module generates a first control signal. The first switch module switches to the first state and transmits the first audio signal. If the first audio signal is not generated, the judgment module generates a second control signal. The operation module generates a selecting signal. The second switch module switches to a second audio signal according to the selecting signal and transmits to the first switch module. The first switch module switches to the second state and transmits the selected second audio signal. The play module plays the audio signal.