Hey Siri, you’ve become smarter! Thanks to iOS 9, Siri will work a lot better and perhaps a very useful feature is that Siri will now respond only to your voice.
On all iPhone models, you can activate Siri by saying “Hey Siri” when the device is plugged in. Now, with the launch of the iPhone 6S and iPhone 6S Plus, Siri is active all the time, whether it is plugged in to a power source or not, and that’s because of the new iPhone’s dedicated components which help the device to be always listening.
Teaching Siri to recognize only your voice
With the launch of iOS 9, Apple gives you the ability to teach Siri your voice so that it only recognizes your voice and not others’ voices. This would mean less annoyance, and any other person within reach of your iPhone won’t be able to give a command to your device.
So here’s how you can train Siri to recognize your voice. You will not be prompted to go through this setup process, but you will need to manually launch this process. To do this, you will need to go to the Settings app > General > Siri.
Next, turn the feature OFF and then turn it back ON. Once you enable it, the setup process starts. You will first be asked to repeat “Hey Siri” three times, and then two other commands.
When you are doing this, you should ideally do it in a quiet place so that the process goes smoothly.