CSS 听觉参考手册
听觉样式表
听觉样式表可把语音合成与音响效果相组合，使用户可以听到信息，而无需进行阅读。
听觉呈现可用于：
- 视觉能力低弱的人士
- 帮助用户学习阅读
- 帮助有阅读障碍的用户
- 家庭娱乐
- 在汽车中使用
听觉呈现通常会把文档转化为纯文本，然后传给屏幕阅读器（可读出屏幕上所有字符的一种程序）。
听觉样式表的一个例子：
h1, h2, h3, h4
{
voice-family: male;
richness: 80;
cue-before: url("beep.au")
}
上面的例子可以让语音合成器演奏一段声音，然后用男性的声音读出标题。
CSS2 听觉参考
W3C : "W3C" 列的数字显示出属性由哪个 CSS 标准定义（CSS1 还是 CSS2）。
| 属性 | 描述 | 值 | W3C |
|---|---|---|---|
| azimuth | Sets where the sound/voices should come from (horizontally) | angle left-side far-left left center-left center center-right right far-right right-side behind leftwards rightwards |
2 |
| cue | A shorthand property for setting the cue-before and cue-after properties in one declaration | cue-before cue-after |
2 |
| cue-after | Specifies a sound to be played after speaking an element's content to delimit it from other | none url |
2 |
| cue-before | Specifies a sound to be played before speaking an element's content to delimit it from other | none url |
2 |
| elevation | Sets where the sound/voices should come from (vertically) | angle belo level above higher lower |
2 |
| pause | A shorthand property for setting the pause-before and pause-after properties in one declaration | pause-before pause-after |
2 |
| pause-after | Specifies a pause after speaking an element's content | time % |
2 |
| pause-before | Specifies a pause before speaking an element's content | time % |
2 |
| pitch | Specifies the speaking voice | frequency x-low low medium high x-high |
2 |
| pitch-range | Specifies the variation in the speaking voice. (Monotone voice or animated voice?) | number |
2 |
| play-during | Specifies a sound to be played while speaking an element's content | auto none url mix repeat |
2 |
| richness | Specifies the richness in the speaking voice. (Rich voice or thin voice?) | number |
2 |
| speak | Specifies whether content will render aurally | normal none spell-out |
2 |
| speak-header | Specifies how to handle table headers. Should the headers be spoken before every cell, or only before a cell with a different header than the previous cell | always once |
2 |
| speak-numeral | Specifies how to speak numbers | digits continuous |
2 |
| speak-punctuation | Specifies how to speak punctuation characters | none code |
2 |
| speech-rate | Specifies the speed of the speaking | number x-slow slow medium fast x-fast faster slower |
2 |
| stress | Specifies the "stress" in the speaking voice | number |
2 |
| voice-family | A prioritized list of voice family names that contain specific voices | specific-voice generic-voice |
2 |
| volume | Specifies the volume of the speaking | number % silent x-soft soft medium loud x-loud |
2 |