A content output apparatus, methods for controlling a content apparatus, and a mobile apparatus are provided. The content output apparatus includes a receiver configured to receive content, a display configured to output a video signal of the content, a speaker configured to output an audio signal of the content, a communicator configured to transmit the audio signal to at least one external speaker, and a controller configured to determine whether the audio signal is related to the video signal, and display a user interface screen for inducing a selection of an output mode which transmits the audio signal to the at least one external speaker with a communication method corresponding to the determination result among a plurality of output modes via the display.