[whatwg] [HTML5] Accessibility question

Benjamin Hawkes-Lewis bhawkeslewis at googlemail.com
Tue Apr 1 00:00:51 PDT 2008


Henri Sivonen wrote:

>> I understand your point about superfluity being defined by the 
>> presentation (one could argue the same about relevance...). Aural CSS 
>> seemed, at one point, like it would make sense for handling such 
>> issues. However, since screen readers read the "screen" media styles, 
>> it doesn't really help.
> 
> More to the point, it is unreasonable to expect casual authors to supply 
> sensible aural CSS even if it were supported.

I think that assumes authors would need to devote the same energy to
overriding default aural CSS that they spend on overriding default
screen CSS. I don't think that's the case because the default 
presentation is mostly fine. Yes, there are problems with pronunciation, 
but CSS seems to the wrong layer for solving questions of meaning. And 
yes, you might want to specify default voices for different 
interlocutors, but that's an edge case. Customizations of this sort run 
the risk of colliding with the native use of alternate voices for 
semantics by speaking agents (e.g. the JAWS Web Rent-a-Crowd scheme), so 
they aren't necessarily desirable in run-of-the-mill web content.

The main uses of speech CSS, were screen readers to apply it, would 
probably be to force rendering of content with display and to silence 
content with display or speak. I don't think this would be radically 
more difficult than the commonplace display: none; technique that 
currently doesn't work and it would arguably be as easy as the 
off-screen hiding technique that sort of does.

So I don't think it's especially unreasonable.

> As currently drafted, ARIA has aria-hidden, which is essentially a less 
> elegant duplicate of HTML5 'irrelevant'. As far as I can tell, ARIA 
> doesn't specify aria-hidden=false as overriding display: none; in 
> accessibility API exposure. (But then in general, ARIA doesn't specify 
> processing requirements in the way we expect from HTML5.)

Hmm … http://www.w3.org/TR/wai-aria/#hidden seems to be specified as
equivalent to visibility: hidden, a property that theoretically
shouldn't affect speech rendering but does (accidentally) hide content 
from screen readers. It doesn't say anything about display: none;.

It's not at all clear that it's intended to meet the same use-case of 
@irrelevant, but if it is then I doubt it will help solve these problems 
arising from different media and modes of access.

How are you envisaging aria-hidden might help?

--
Benjamin Hawkes-Lewis





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