An HMD including an image display unit mounted on a user's head to display an image, a right earphone and a left earphone to be installed in the user's right and left ears to output sound based on a sound signal of a right channel for a right ear and a sound signal of a left channel for a left ear, a second communication unit configured to receive a sound signal, and a control unit configured to assign a sound signal for sound associated with a displayed image displayed by the image display unit and the sound signal received by the second communication unit to the left channel and the right channel to output the sound signals as sound.