A broadcast receiver includes: a signal receiving unit which receives a first signal and a second signal different from the first signal; a signal processing unit which processes the first and second signals; a communication unit which communicates with an external device to output a sound; and a controller which controls the signal processing unit and the communication unit to process a video signal of the first signal to be displayed and to process an audio signal of the second signal to be transmitted to the external device if the first signals contains the video signal and the second signal contains only the audio signal.