With iOS 8, you can talk to Siri without pressing the Home button at all. Turn this on by going to Settings, General, Siri and switching on “Hey Siri.” Now you can simply speak things aloud starting with the words “Hey Siri.” For instance, you could say “Hey Siri, tell me a joke.” and Siri will respond. You never have to touch your device. The catch is that you need to have your device plugged in, presumably because this feature would drain the battery pretty quickly.
Mac Video Tutorials and Tips for Apple Users
