Google 4 Manual Book page 102

screen, you don't have to touch anything.
Just say "Google."
Next, speak the terms to search for or the
Voice Action to perform. For more details on
Voice Actions, see
The ability to trigger a search or action by
saying "Google" is called hotword detection.
To turn it off or on, start from the Google Now
screen and touch Menu > Settings > Voice >
Hotword detection.
IMPORTANT: To detect when you say
"Google" to launch Voice Search or
Voice Actions, Google analyzes sound
picked up by your phone's microphone
in intervals of a few seconds or less.
The sound is immediately discarded
after analysis and is not stored on the
device or sent to Google.
For more information about Voice Actions,
USE GOOGLE NOW & SEARCH
"Use Voice Actions."
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