True, Siri could do this in iOS 8, but the feature is turned off by default in iOS 9 and also offers better voice-recognition technology—meaning, presumably, that Siri won’t start listening if someone else grabs your iPhone and says “Hey Siri.” If you decided to turn this feature on, iOS 9 walks you through a quick setup process to help Siri learn your voice tone a bit better.
First, you have to activate this feature. Go to Settings > General > Siri, and then toggle on “Allow ‘Hey Siri.’” The next time you summon Siri with a command—either by holding down on the Home button or by calling out “Hey Siri” when your iOS device is plugged in—you’ll be prompted with a setup screen.
Then, you just follow the onscreen instructions. The setup simply requires you to say “Hey Siri” three times to detect different variations in tone you may use.
It’s similar to setting up Touch ID, where you lift your finger up and down repeatedly on the Home button so that it detects your prints from various angles. It also asks for you to say two commands—“Hey Siri, how’s the weather” and “Hey Siri, it’s me!”
...and that’s it! Now, Siri will be ready to listen in whenever your iPhone is plugged in—perfect for hands-free use in the car, or if your iPhone is charging across the room.
Have any questions about this feature Let us know in the comments below, and we’ll try to address them.