HDMI ARC (Audio Return Channel) is a feature that allows audio to be sent and received through a single HDMI cable. This means that you can connect a variety of devices, such as Blu-ray players, set-top boxes, and gaming consoles, to your TV, which will then channel all the audio outputs to the HDMI-ARC connected soundbar or home theatre system. HDMI-ARC is also capable of passing high-resolution audio, including formats like Dolby TrueHD and DTS HD Master Audio. Using HDMI-ARC, you can also control the volume of HDMI-ARC connected devices using your TV remote.

To use HDMI ARC, you need a high-speed HDMI cable, which is usually included with Smart TVs. You need to connect one end of the cable to the HDMI ARC port of your Smart TV and the other end to the desired HDMI-ARC enabled device. Once both devices are turned on, your TV will automatically connect the ARC.

Its important to note that not all TVs support ARC despite coming out after HDMI 1.4 was launched as a standard, but nearly all will. Additionally, the HDMI-ARC functionality is only available through the specific port on the TV or One Connect Box, and the external speakers need to be compatible.

Enhanced Audio Return Channel (eARC) is an updated version of HDMI ARC that supports higher bandwidth and can transmit more advanced audio formats, such as Dolby Atmos and DTS:X.