“Lumia 930, 1520 and Lumia Icon will get “Hey Cortana” voice activation as part of the Lumia Denim update”, says the official wording from Microsoft. This feature would basically allow certain Denim-powered phones to be on the lookout for the “Hey Cortana” keyword, which would activate the functionality to further improve the user experience. This is based on chipset features which enable the phone to listen to certain keywords (in this case, “Hey Cortana”) in order to trigger a feature.
However, in the UK, the O2 Lumia 930 Denim update rollout has begun; strangely, the “Hey Cortana” feature is missing. On the official forums, the carrier has posted this update, through its social media team: “I understand many of you are unhappy around an issue with Cortana functionality being missing – please leave this with me and the device team, we’ll find out what the issue is and report back.”