Similar problem. Normal conversation and radio broadcast in vehicle activates touchless control. Also, anyone's voice saying "Ok, Google" will launch the control. Not a huge deal, and I love this phone, but what do you guys recommend to lessen this occurrence?
Mine has come on couple times randomly but it wont turn on with anyone else's voice. A at&t rep was the only one to get my ok Google to turn on by voice.
Mine did it a couple times when listening to a specific sports talk show on the radio. The one guy's voice must be similar enough to mine over the speakers. I calibrated it again and it hasn't happened since.
Mine is coming on several times a day now. Yes, I have re-trained it and that did not solve the issue. It comes on while I am listening to TV. Having a conversation with friends, even in the car with the radio on.
I guess my only option is to turn off the Touchless Control.
The only time I've had problems was by saying "OK Google Now" differently during set up, just to see what happens. Man, just about anything will set it off if you do that.
You really do need a place that is COMPLETELY quiet to set it up.