HTML and CSS Reference
T IP More details on these properties can be found at www.w3.org/TR/CSS21/aural.html.
T IP While aural properties may seem to have little use in visual presentation, some CSS authors like
to use aural style sheet rules to confuse certain browser versions to overload properties, such as
what the Box Model hack does. This technique is not suggested and scripting logic should be
CSS3 has also taken up the cause of aural style sheets with its Speech module
(www.w3.org/TR/css3-speech/). It introduces new values to improve pronunciation, like
phonemes , but also seems to simply rename features; for example, stress becomes
voice-stress , pitch becomes voice-pitch , and volume becomes voice-volume . The
only browsers that have any sense of support for this are experimental versions of Opera
on Windows, and here you may require a -xv- prefix; for example, -xv-voice-stress
instead of voice-stress .
The renaming effort regardless of prefix seems only helpful in the few places where
aural terms might be ambiguous when mixed with other presentation. However, given how
little speech-browsing technology exists, and noting that which does exist often ignores
aural-focused CSS properties, looking even further ahead to CSS3 might seem to be a bit of
a waste of time.