The Samsung TVs do perform voice recognition through the mic on the TV as well as on the remote (well, at least mine, which is a couple years old, does). Even if you have the voice recognition setting turned off, the one on the remote still works by pressing the button.
The non-remote one does use a trigger word ("hi tv" by default) and it definitely does that processing locally (I know because i disconnected my TV from the internet and tried it). Basic commands ("channel up" etc) also worked. I don't know what else to try to figure out when it goes out to the internet. I'd also add that the camera/microphone have a very visible hardware off (which I keep off, because life is too much like 1984 already).
The non-remote one does use a trigger word ("hi tv" by default) and it definitely does that processing locally (I know because i disconnected my TV from the internet and tried it). Basic commands ("channel up" etc) also worked. I don't know what else to try to figure out when it goes out to the internet. I'd also add that the camera/microphone have a very visible hardware off (which I keep off, because life is too much like 1984 already).
Again, this is a 2013 model.