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[CSS21] WAI Issue 1: Relegation of Aural CSS to an informative appendix & the Deprecation of the aural media type [DRAFT]

From: Gregory J. Rosmaita <oedipus@hicom.net>
Date: Tue, 11 Dec 2007 03:02:47 +0000
To: wai-xtech@w3.org, wai-liaison@w3.org
Message-Id: <20071211030159.M70352@hicom.net>

[Reviewer's Note: this post refers to the Candidate Recommendation draft 
of CSS 2.1,
comments upon which are due by 20 December 2007]

Given the following use case:

Aural rendering is used to provide supplemental contextual and semantic 
markers for an individual with either limited vision, or a limited 
view-port, such as that obtained by using a screen-magnifier application, 
which displays strings of text in isolated viewports, with earcons 
aural cues) set to "on", but without speech output.  Such a user uses 
aural cues, provided by such extant mechanisms as:


to supplement that user's constrained point of view.  Note that this use 
case includes those who fall under the purview of such organizations as 
Recording for the Blind and Dyslexic (http://www.rfbd.org)

Note that some users will benefit from viewing portions of the screen 
using a screen-magnifier and aural cues; but that there are also those 
who not only need isolated portions of the visual canvas rendered for 
but whose understanding and ability to interact with the document 
greatly from supplemental synthesized speech;

How, then, can speech be seperated from audio?  The Style WG should be 
wary of the seperation of speech and pure aural rendering rules, as 
there is one modality being addressed: the aural canvas, whether that 
includes speech-synthesis or purely earconic sounds.

The question, therefore, is this:  What is the point of changing the 
media type from aural to speech?  Speech synthesizers are aural 
but they rely on a third party application (optimally, a DOM-aware user 
agent) in order to obtain the content, flow, etc. of the speech-output.  
If a user agent supports speech, as does FireVox, it also needs to 
the purely aural (earconic) portions of the media rule; speech 
synthesizers are not user agents, they are more akin to browser helper 
objects (BHO) than they are to user agents per se.


The deprecation of the aural media type in favor of the speech 
media type, is unacceptable, as there are valid use cases where an 
individual benefits from supplemental earcons that sound while 
viewing the visual canvas through a screen-magnifier type view-port, 
without speech output, but with support for a pure audio 
(non-speech) overlay; likewise, there is the use case of an 
individual who benefits from supplemental speech, as well as a 
limited viewport and aural orientational and contextual cues.  

Why is it necessary for Aural CSS2.1 to remain normative?  The 
aural cascade will enable an author to offer visitors is a choice 
between "verbose" "terse" and "earconic" overlays. SSML may be 
where the money and resources are currently devoted, but Aural CSS 
is far superior for speech-output dependent computer users (that 
is, the average end user) because things aren't hard coded, but 
are subject to user over-rides. It's obviously a lot easier to 
wizardize a "modify this site's aural styling", which would allow 
the end user the final say over what is spoken and how, than to 
edit an SSML document's document source.

An added benefit of retaining the purely aural portions of ACSS 
is that, if both speech and purely aural styling are addressed 
in the same stylesheet, it reduces the burden on the author, 
allows for end-user override, and it increases the probability 
of the implementation of both forms of painting to the aural 


1. The PF WG requests that the editors and Working Group de-deprecate the 
   "aural" media type and deprecate the "speech" media type

2. The PF WG requests that Appendix A be renamed to Chapter/Section 19 
   made normative

CONSERVATIVE, n.  A statesman who is enamored of existing evils,
as distinguished from the Liberal, who wishes to replace them 
with others.         -- Ambrose Bierce, _The Devil's Dictionary_
             Gregory J. Rosmaita, oedipus@hicom.net
  Camera Obscura: http://www.hicom.net/~oedipus/index.html
Received on Tuesday, 11 December 2007 03:03:06 UTC

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