ARC (Audio Return Channel) allows audio signal from TV to be transmitted back to the home theatre receiver via HDMI version 1.4 cable.
General ARC connection advice
There is no need for connecting a second cable between the TV and the home theatre system. As a result, you can listen to the audio of the TV with the sound quality of the home theatre. Note: Both your TV and the home theatre system need to be ?ARC supported? in order to utilize this feature.