# 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 |