I believe secure settings Google Voice input will activate the launch activity for Google Now Voice Search, and not pass any input into tasker.
Switching locale will require root also. (Switching keyboard)
I could be mistaken, but I believe AutoVoice does not require access online to interpret voice recognition results.
AutoVoice might work for what you're looking for.
In CM10.1 you can find it in the Google now menu. Might be the same for CM10.²
Jay M
Weird :/ You sure your looking in the right place? what I did was added a Google Search Bar Widget to my home screen then tapped the bar pressed menu/voice and it was in there. If that's what you did then maybe it was removed on your ROM.
Jay M