The EPUB 3 Working Group has just published a Working Group Note of EPUB 3 Text-to-Speech Enhancements 1.0. This document describes authoring features and reading system support for improving the voicing of EPUB 3 publications.
The EPUB Working Group of the International Digital Publishing Forum (IDPF) first defined a means of integrating the Synthetic Speech Markup Language and pronunciation lexicons in EPUB 3.0 so that EPUB Creators could improve the rendering quality of text-to-speech (TTS) playback in Reading Systems. The ability to include cascading style sheets also allowed EPUB Creators to access the in-development speech properties of the CSS Speech module. However, although there has been some authoring uptake of these technologies, support in Reading Systems has yet to materialize to a level where these technologies are considered stable. Consequently, these technologies are now published as a W3C Working Group Note.
Original source: https://www.w3.org/blog/news/archives/9182