Back in the day when picture tube TVs were still very common, my father used to have a headset connected to his TV. I'm thinking of wanting to do the same with my LED TV where normally would watch with soubd over the TV and occasionally when needed watch with my headset on. I'm also buying a Shield TV Pro soon-ish. Is there an easy way in Android TV to select an alternative sound output instead of the HDMI out to the TV?
Shield Pro has audio output in the settings, you can even pin it to Quick Settings for even easier access.
The Mi Box has RCA audio outputs as well as HDMI, and audio runs through both at all times. You may need to run it through an amplifier to connect to headphones.
Best bet would probably be to use your TVs headphone jack if available.
As others have said, all Android TV devices have bluetooth and that works really well for headphones. But if you want something more instant, the Shield gaming remote has a regular 3.5mm headphone jack. Plug in and the audio flips automatically, unplug and it flips back to the tv/speakers.
Most Android TV devices, if not all, will have bluetooth. The Shield does for sure.