Why does my iPhone X start reading text automatically? My iPhone X frequently starts to speak something when I’m outside. It never happens when I’m at home.

The content seems to be the text in the app, though I’m not sure what it speaks since it is not my native language. This is especially common when I use a navigation app like Baidu Map or Ofo.

I usually must stop the voice by tapping the X button, but it is not always apparent.

My questions:


Is this only on iPhone X or from iOS 11? What functionality is it?
What button triggers it? I don’t feel I push some button, though...
Is it possible to disable it?
I found that this happens when I use two fingers and swipe from the top of the screen. 

The solution

Go to Settings | General | Accessibility | Speech | Read aloud on the screen

(maybe the text is slightly different as my language is set to Chinese)