New Apple TV adds ARC support for universal TV audio passthrough to HomePod speakers - 9to5Mac
Amazon.com: Avantree Orbit Bluetooth 5.0 Audio Transmitter for TV with 5.1 Surround Sound Passthrough Support, Class 1 Long Range, LED Display, Dual Link, 100% TV Compatibility Delivers No Lip sync Delay : Electronics
File:Audio passthrough.png - GNU Radio
Our TV Input Tests: Audio Passthrough - RTINGS.com
Passthrough: Dolby Digital works, DTS do not. - Printable Version
Microsoft will soon enable audio passthrough on the new Xbox