Google's search app for Android now starts a new voice search when you say the hotword "OK Google" instead of just "Google". Additionally, the new hotword also starts a fresh search while the app is displaying results from the previous search. This change comes bundled with the latest (2.8.7) update and activates when you manually update the language pack.
"OK Google" is also the hotword for the iOS Google search app and the Google Chrome desktop browser. The hotword for those products dovetails with Google Glass' "OK Glass" search call-up as well. The change was made in an effort to reduce false hotword recognition; "Google" by itself tended to cause the app some confusion, presumably because that brand name is so often used in everyday conversation.
This minor change is just one part in a company-wide, coordinated push towards a more dependable and natural linguistic interface between humans and machines running Google products. Google's Knowledge Graph, for example, aims not only to answer and converse with users, but to anticipate their queries based on context; "Hummingbird" is another arm of the project.
To activate the new "OK Google" hotword for your Android Google search app, first make sure you have the latest update. Open the app's settings, then select "Voice", "Language", and finally "Offline Speech Recognition". Download the language pack update from there and restart the app. "OK Google" will be your new search hotword from here on out.
VIA: Android Police