Limitations:
- Only one person can train Hey Cortana at a time.
- Only the Hey Cortana phrase can be used as a keyword.
- When Cortana is triggered under the lock screen, it will not perform all possible commands – it will respect your privacy.
- The Hey Cortana feature uses battery power. By default Hey Cortana is off.
How to train?:
- Select Settings > Hey Cortana
- Find quiet place and once you are ready to start the training, tap start and follow the instructions.
- Remember to talk in your normal voice, and say Hey Cortana 5 times.
Battery Saver:
Hey Cortana is turned off automatically when the Battery Saver mode starts (at less than 20%), and automatically turns back on when the Battery Saver mode ends (at more than 20%).
Recent Windows 10 technical preview leaks have hinted about possibility of Hey Cortana coming to devices even without Snapdragon 800.