Definition

Describes a resource that offers both audio and text, with information that allows them to be rendered simultaneously. The granularity of the synchronization is not specified. This term is not recommended when the only material that is synchronized is the document headings.

Examples

Example 1 — EPUB 3
<meta property="schema:accessibilityFeature">
   synchronizedAudioText
</meta>
Example 2 — EPUB 2
<meta name="schema:accessibilityFeature"
      content="synchronizedAudioText"/>
Example 3 — Audiobooks
"accessibilityFeature": ["synchronizedAudioText"]

Explanation

The synchronizedAudioText value is used to indicate that synchronized playback of prerecorded audio with text highlighting is available.

Synchronized playback can help new language learners follow the text and hear how it is pronounced, for example, but is also helpful for users who need only one or the other modality. Audio playback can be used to provide an audiobook experience for users who are blind or have low vision, while text highlighting can help users who have difficulty following lines of text.

Text and audio synchronization is typically provided using the SMIL language (e.g., in DAISY talking books and EPUB 3 media overlays).

See the media overlays knowledge base page for more information.

EPUB 3 media overlay file.

<smil xmlns="http://www.w3.org/ns/SMIL"
      xmlns:epub="http://www.idpf.org/2007/ops"
      version="3.0">
   <body>
  	<seq id="id1" epub:textref="chapter_001.xhtml"
             epub:type="bodymatter chapter">
            <par id="heading1">
               <text src="chapter_001.xhtml#c01h01"/>
               <audio src="audio/mobydick_001_002_melville.mp4"
                      clipBegin="0:00:24.500"
                      clipEnd="0:00:29.268"/>
  	   </par>
  	</seq>
	  …
   </body>
</smil>

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