Good point!..Why would Siri not answer to "Hey Siri"? You're still saying Siri.
Hi, do you know if this option is just for english language setting? My iPhone language is spanish, country Mexico and I don't have this option. Siri just activates if I say "oye Siri", if I say just "Siri" it does nothing.In the Siri settings it says you can invoke Siri with Hey Siri and/or Siri.