HTML and CSS Reference
envision a time in the near future when you may be able to take advant-
age of some or all of these properties.
184.108.40.206. The volume property
The most basic aural property is volume . It accepts numeric length or
percentage values along with a few keywords corresponding to preset
Numeric values range from 0 to 100, with 0 corresponding to the min-
imum audible level and 100 being the maximum comfortable level. Note
that 0 is not the same as silent, as the minimum audible level in an en-
vironment with loud background noise (like a factory floor) may be quite
Percentage values compute an element's volume as a percentage of the
containing element's volume. Computed values less than 0 are set to
0; values greater than 100 are set to 100. Thus, to make an element
twice as loud as its parent element, set the volume property to 200% . If
the volume of the parent element is 75, the child element's volume gets
set to the limit of 100.
You also may specify a keyword value for the volume property. Here,
silent actually turns the sound off. The x-soft value corresponds to a
value of 0 ; soft is the same as the numeric volume of 25; medium is 50,
loud is 75, and x-loud corresponds to 100.
220.127.116.11. Speaking properties
Three properties control whether and how text is converted to speech.
The first is speak , which turns speech on and off. By default, the value
of speak is normal , meaning that text is converted to speech using stand-
ard, locale-specific rules for pronunciation, grammar, and inflection. If
you set speak to none , speech is turned off. You might use this feature to
suppress speaking of secondary content or content that does not readily
translate to audio, such as a table.