Back in June, Apple introduced a new iBook feature it calls Read Aloud, which is similar to Nook’s Read to Me feature in that it provides a human voice narration that syncs to the onscreen text. In both commercial cases, the feature is meant primarily for children’s books.

Now Apple has updated its iBookstore Assets Guide to include instructions on how to add a Read Aloud narration track to your EPUB file. You can’t access the latest guide unless you’re a registered iTunes Connect member, but eBookNewswer has printed part of the relevant section:

“You can create a Read Aloud book by adding Media Overlays to a Fixed Layout book. A Media Overlay is an EPUB-specific Synchronized Multimedia Integration Language (SMIL) file that can be used to sync audio with text, allowing readers to follow along as the words are read aloud. An additional feature gives you the option of highlighting words as they are spoken.”

Fortunately, SMIL isn’t an Apple-created overlay, but a W3C recommended XML markup language that is used to control the timing of multimedia presentations, and in fact it’s been included in the proposed EPUB 3.0 Media Overlay specs.

By the way, the iPad also has a TTS function that will read most iBook EPUB files to you. It relies on the built-in voiceover functionality of iOS, which I guess is how it flew under the radar of the Authors Guild and anyone else who attacked Amazon’s Kindle TTS feature. In my tests, however, it doesn’t work on competing ebook apps.

5 Aug 2011 / Update on VoiceOver, the iOS TTS feature: I re-tested the most current Kindle, Kobo and Nook iPad apps after reading the comments below. Kindle doesn’t work at all (not even interface buttons are read aloud by VoiceOver). Nook will read some interface buttons but nothing else. Kobo actually does work, but it’s a little clumsy—you have to launch VoiceOver at the start of a chapter or section (at least in my tests), and although VoiceOver will continue to read the section after the first page, the onscreen page won’t advance. At first I suspected the varying levels of functionality had to do with what version of iOS was required, but VoiceOver has been available since iOS 3.0. Of the current app versions, Kindle requires iOS 3.0, Kobo requires iOS 3.2, and Nook requires iOS 4.0.

Via eBookNewser


  1. I didn’t understand what was meant by, “… it doesn’t work on competing ebook apps.” Assuming that “it” refers to the TTS function in iOS, one is left to guess as to why. Since Apple’s TTS has been around for a very long time and is well documented on Apple’s developer site, could it be that those other apps simply don’t attempt to make the requisite calls to that API?

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