Squeak Accessibility for the blind
Boris.Gaertner at gmx.net
Fri Dec 10 15:09:38 UTC 2004
> >For a blind user the web browser has to be adapted anyhow. The basic
> >functions are there in Celeste
> Actually, I was thinking about the more complex HTML and style sheet
It is perhaps not useless to say that the W3C specifications
describe in great detail what help an user agent should offer to
visually impaired users. In my impression, the specifications
were improved a lot over the last years.
This is a passage from Html 4.0, Section 9.2.1.:
"Generally, visual user agents present EM text in italics and
STRONG text in bold font. Speech synthesizer user agents
may change the synthesis parameters, such as volume,
pitch and rate accordingly. "
Section 11.4 of the same document contains recommendations
for table rendering by non-visual user agents.
The most interesting specification is perhaps CSS2.
Among other things it defines aural styles. With these
styles you can
* associate different voices to different text entities
* specify how numbers are read: digit by digit or
* add pauses and aural cues
For stereo equipment, you can even define the virtual
positions of different speakers!
Here are some examples in
<acronym lang="en-US" style="speak : spell-out">HTML</acronym>:
<span lang="en" style="speak-numeral:digits">72 54 23 12</span>
is a good style for a phone number: It reads the digits one by one.
The following is a piece of HTML that contains all
necessary specifications to read an amount of money in US english:
Abbreviations are another topic for speach synthesis:
<abbr lang ="en-uk"
title ="British Broadcasting Corporation"
title ="North Atlantic Treaty Organisation"
style="speak : normal">NATO</abbr>
The first abbreviation should be pronounced letter by letter
the style for the second abbreviation requires phonetical
The problem is that these features are not always
implemented - other 'unique selling points' are often
given a higher priority. Another problem is that many
document authors simply do not care about language
and speach support.
Scamper does not currently support styles, but we
have speach support and I think we could implement
support for aural styles.
Question to our academic teachers:
Wouldn't that be a beautiful task for a student?
Just dreaming with open eyes
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