Why did voice commands stop working on my Android phone?

Episode 1060 (2:21:16)

Dave from Hamilton, MT

Dave has a Motorola Razr M and he got a new bluetooth headset, but one day it just stopped working with voice command. Leo says to look into the Android settings. There should be an option that says "ignore voice command," which could be enabled. He should also check Google Now. Leo says it's likely Android got updated and now he probably has to opt into Google Now to make it work.