I figured that since the issue was that Moto Voice wasn't actually 'hearing' anything (as was evident when I tried to re-train it the command phrase), something else was using that resource. Now, b/c you (and someone on Moto Support forums) are having this issue, yet you aren't running NPR One, it seems likely that the issue is either with Moto Voice or the OS not allowing access to a resource in tandem with others. I'd restart your phone, then fire up whatever audio app you use most commonly, and try Moto Voice. If it still works, move to the next audio app, try again. Eventually, when it stops working, stop the services started by the most recent app - one by one - and figure which service is also using the same resource. If we can find several, I'd think it easier for the folks at Moto to find some commonality.