On my iPhone 6, how do I tell Siri I'm done talking? Is there a gesture, or a word? Like "stop" on a old-timey telegraph? When I'm giving Siri commands, she continues to listen well after I'm done speaking. Sometimes it's in the car, or at home with background noise. I guess she's picking up that noise waiting for silence? I don't remember this being an issue on my iPhone 5.