@aral whenever I turn off my Android TV, it turns itself back on after a few minutes and then turns off again a minute or two later. I presume it is listening because why else turn back on? We don't converse during the "restart" - just observe some moments of quiet reflection on the state of the world.
I would not know of the restart interval, except for the unusual way my TV audio is configured - instead of an HDMI connection to a soundbar, I have a bluetooth connection to a separate music system. When the bluetooth connection is made, the sound system announces the connection (not the TV).