Google Search has been updated, adding the ability to activate Google Now from any screen or app on your device. This includes the lockscreen, which will now listen for your "Ok Google" command.
Always-on listening has been available to Moto X users because of the phone's always-listening chip, this is the first time that device-wide voice activation of Google Now will be available to Android at large. You can turn on the feature by going into Google Search's Voice settings area and selecting "Ok Google" Detection. From there, you'll be able to choose From any screen and, separately, From lock screen.
In addition to voice activation in any app, Google Search adds Audio History. This feature allows Google Search to learn the sound of your voice, making your searches more accurate. You can manage your Audio History, as well as turn it on and off, in the Google Search Voice settings.
The update is currently rolling out through the Google Play Store, so it might take some time before you see it. What do you think of these updates to Google Search? Tell us below in the comments.