You have to press the key combinations (fn+spacebar which is the default or a customized set) or the icon. It'll be cool if they implement "Hey Siri!" as an option.On other note, can Siri listen without pressing Siri icon? Kinda useless tbh if you must press the button first...
I bet when you charge your laptop it has that feature like the iPhone 5s & 5 , but not always on like the new iPhone 6s and 6s plus
There is a way to enable Hey Siri, see this:
Here is my tutorial: How to enable Hey Siri activation on a mac with Sierra
I implemented the "Hey Siri" functionality some time ago. While that made it easier to talk to "her", "she" got so many things wrong, or was unable to fulfill my request so many times, that I finally just gave up. As I have said before, I find Siri really half-baked, and a product that should not have been let out the door quite yet. The app needed a lot more polish first, in my view. I haven't used Siri since. Besides, I don't feel comfortable talking to a machine anyway. I much prefer a quiet work environment.Here is my tutorial: How to enable Hey Siri activation on a mac with Sierra
It has a few more details than the 9to5mac article.