Text to Speech with Speak Selection Even Better in iOS 6 – Highlights Words as Spoken | Eclectic Technology | Scoop.it
From paulhami.edublogs.org - October 1, 2012 9:49 PM

Speak Selection has been an accessibility feature since iOS 5. With the release of iOS 6 you may choose to have each word highlighted as it is spoken. For more information click through to this article for screen shots of what you need to do.