How to tell the mode (Transparency, noise cancellation or none) of airpod pro when it connects to the Apple TV? I can connect the audio of my AppleTV to my Airpod Pro.

However there is no obvious which mode the Airpod Pro are in from the Apple TV user interface.

I tried to use Siri to find it out, but it only says I can use the remote to control volume.

Is there any way I can find it out, other than playing music loudly from another source so I can tell by taking off the ear bud?
Since the AirPods don’t have a mode until they are in your ears there’s no mode before you have them live. 

Once they are live that data isn’t exposed on AppleTV. I would recommend using the switch control on your AirPods to cycle the mode until you know what mode they are in by listening.