After on-body detection, Google is now adding a new option to the Smart Lock feature in Android. The company has slowly started rolling out the new “Trusted Voice” option to various Android users, which allows them to unlock their Android device by just saying “OK Google.”
The company warns users at the time of setting up “Trusted Voice” that it is less secure than password, PIN or pattern locks as someone else with similar voice or recording of their voice could unlock the device.
The feature uses the “OK Google” voice training that most users already feed in their phones for Google voice search. The exact details about the feature are unclear at this moment, but more than an unlock mechanism, it seems like an extension of “OK Google” hotword support to locked and sleeping devices. Earlier, you could only use “OK Google” when your screen was on, granted that you had selected the option in settings.
We hope to see an official announcement soon. To remind you, Smart Lock is only available in Android devices running Lollipop.