With the new Apple TV 4K, you can play any audio from your TV on your HomePod speakers.
Apple TV 4K Setup Video and Audio for 4K HDR and Dolby Atmos
Apple has revealed that the new Apple TV 4K will allow users to enable HDMI ARC and eARC, which will allow audio from any input source to be streamed to HomePod speakers. According to 9To5Mac, Apple enabled the ability for older versions of Apple TV to stream audio to HomePod speakers last fall.
That software update only allowed audio from Apple TV itself to be shared. Apple TV 4K will allow all audio from all your TV inputs to play through your HomePod, if your TV supports ARC output.
Before you can take advantage of the new ARC feature, you'll need to set up your system properly. Apple says that the HomePod speaker will need to be plugged into the same room as the Apple TV 4K, after which you'll need to set the HomePod as the default audio output. Once you've done that, you can enable the Audio Return Channel feature, which is currently in beta.
