How can I make Siri read text on my iPhone?
You can tell Siri to speak selected text displayed on your iPhone. By default the option is switched off, so by following a few steps you can enable Siri to read.
1. Navigate to Settings -> General -> Accessibility
2. Select Speak Selection -> Speak Selection -> ON
Now when text is selected, there will be a speak option displayed. Tap speak and Siri will read the text to you. To adjust the speed of speaking adjust the bar under Speaking Rate.
In fact, even the iPhone 3GS with recent iOS firmware will read text. Siri is not necessary for the feature, as it was part of Voice Control on older models.