While asking Cortana various questions on Windows Phone 8.1 is natural, the way in which one enables the personal voice assistant isn't quite as fluid. Users need to press down on the Search key or press the Live Tile and microphone before Cortana enables, and while it's not difficult there are better solutions available.
One of the solutions is passive-voice activation, which is something users of the Xbox One with Kinect should know. Passive-voice activation allows users to engage the AI or system simply by using their voice. Likewise, the Motorola Moto X with Android can also activated by explicitly stating 'Ok, Google Now.' The phone will then come awake, letting users make appointments, starting their music, or sending a text message without ever touching the phone.