Siri lets you use your voice to send messages, make calls, set reminders, and more. Just speak naturally. Siri understands what you say. With a redesigned interface and new, more expressive voice, Siri is more powerful than ever. And the more you use Siri, the better it knows what you need at any moment. Just say “Hey Siri” before a request, and Siri does it. Siri lets you use your voice to send messages, make calls, set reminders, and more. Just speak naturally. Siri understands what you say. Since iOS 8, Siri is now able to listen to and identify music tracks playing nearby at user request.