Aural CSS Sample from W3C

Text and Images from Slide

When using aural properties, the canvas consists of a three-dimensional physical space (sound surrounds) and a temporal space (one may specify sounds before, during, and after other sounds). The CSS properties also allow authors to vary the quality of synthesized speech (voice type, frequency, inflection, etc.).
h1, h2, h3, h4, h5, h6 { voice-family: paul;<br /> stress: 20; <br /> richness: 90; <br /> cue-before: url("ping.au") }
p.heidi { azimuth: center-left }
p.peter { azimuth: right }
p.goat { volume: x-soft }
This will direct the speech synthesizer to speak headers in a voice (a kind of "audio font") called "paul", on a flat tone, but in a very rich voice. Before speaking the headers, a sound sample will be played from the given URL. Paragraphs with class "heidi" will appear to come from front left (if the sound system is capable of spatial audio), and paragraphs of class "peter" from the right. Paragraphs with class "goat" will be very soft.