All style sheets are applied at once, but the order in which they are specified has an influence on
the cascading order. Author styles take
precedence over user styles.
Possible values: <anyURI>
Default value:
Perform text-to-speech
Whether to use a speech synthesizer to produce media overlays.
Whether to use a speech synthesizer to produce media overlays.
This will remove any existing media overlays in the EPUB.