Definition and Usage
This property controls the speaking rate. The default rate for a voice depends on the language and dialect and on the personality of the voice. The default rate for a voice should be such that it is experienced as a normal speaking rate for the voice when reading aloud text. Since voices are processor-specific, the default rate will be as well.
| Name: | voice-rate |
| Value: | [normal | x-slow | slow | medium | fast | x-fast] || <percentage> |
| Initial: | normal |
| Applies to: | all elements |
| Inherited: | yes |
| Percentages: | refer to default value |
| Media: | speech |
| Computed value: | a keyword value, and optionally also a percentage relative to the keyword (if not 100%) |
Syntax
voice-rate: [normal | x-slow | slow | medium | fast | x-fast] || <percentage> ;
Values
- normal
Represents the default rate produced by the speech synthesizer for the currently active voice. This is processor-specific and depends on the language, dialect and on the "personality" of the voice.
- x-slow, slow, medium, fast and x-fast
A sequence of monotonically non-decreasing speaking rates that are implementation and voice -specific. For example, typical values for the English language are (in words per minute) x-slow = 80, slow = 120, medium = between 180 and 200, fast = 500.
- <percentage>
Only non-negative percentage values are allowed. This represents a change relative to the given keyword value (see enumeration above), or to the default value for the root element, or otherwise to the inherited speaking rate (which may itself be a combination of a keyword value and of a percentage, in which case percentages are combined multiplicatively). For example, 50% means that the speaking rate gets multiplied by 0.5 (half the value). Percentages above 100% result in faster speaking rates (relative to the base keyword), whereas percentages below 100% result in slower speaking rates.
Examples
<body>
<e1>
<e2>
<e3>
...
</e3>
</e2>
</e1>
</body>
body { voice-rate: inherit; } /* the initial value is 'normal'
(the actual speaking rate value
depends on the active voice) */
e1 { voice-rate: +50%; } /* the computed value is
['normal' and 50%], which will resolve
to the rate corresponding to 'normal'
multiplied by 0.5 (half the speaking rate) */
e2 { voice-rate: fast 120%; } /* the computed value is
['fast' and 120%], which will resolve
to the rate corresponding to 'fast'
multiplied by 1.2 */
e3 { voice-rate: normal; /* "resets" the speaking rate to the intrinsic voice value,
the computed value is 'normal' (see comment below for actual value) */
voice-family: "another-voice"; } /* because the voice is different,
the calculated speaking rate may vary
compared to "body" (even though the computed
'voice-rate' value is the same) */
