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PLAIN: Proposed rewording for Guideline 1.7

From: John M Slatin <john_slatin@austin.utexas.edu>
Date: Wed, 5 Nov 2003 13:00:11 -0600
Message-ID: <C46A1118E0262B47BD5C202DA2490D1A1DFBD1@MAIL02.austin.utexas.edu>
To: <w3c-wai-gl@w3.org>
Plain language version of Guideline 1.7 plus success criteria, benefits,
and examples


This document contains a series of proposals for a "plain language_
rewording of WCAG 2.0 Checkpoint 1.7 with Success Criteria, Examples,
and Benefits


This is submitted in partial fulfillment of an action item taken by John
Slatin, Katie Haritos-Shay, and Doyle Burnett during a call in late
September or early October, to generate a plain-language version of WCAG


This message is partial in two ways: (1) It addresses only Guideline
(now Principle) 1, Checkpoint (now Guideline) 1.7, and the relevant
success criteria, examples, and benefits.  Other guidelines, etc., will
follow.  (2) It is not really "plain language," in the sense that this
text has not yet been compared to the 1500-word "special lexicon" used
by Voice of America (or other similar lexicons).  Thus it's actually
best understood as an attempt to simplify and clarify.  We're still
working on the formal plain language issues, but wanted to put this out
to start generating discussion.


Items labeled "Current wording" are taken from the September document
Reorg 4, available at http://www.w3.org/WAI/GL/2003/09/reorg4.html
<http://www.w3.org/WAI/GL/2003/09/reorg4.html> .  This document was
current at the time Katie and Doyle and I took on the action item to
attempt a plain language version.  Of course the proposed rewordings
will need to be correlated with later updates.

Current wording for Checkpoint 1.7

1.7 [E3] Foreground content is easily differentiable from background for
auditory default presentations.


Proposed wording for Guideline 1.7

1.7  [E3] In default auditory presentations, make it easy to distinguish
foreground speech and sounds from background sounds.

Current wording for Checkpoint 1.7, SC 1

1.    audio content does not contain background sounds OR the background
sounds are at least 20 db lower than the foreground audio content.




A 20 db difference in sound level is roughly 4 times quieter (or

Proposed wording for Guideline 1.7, SC 1

1. Audio content does not contain background sounds OR the background
sounds are at least 20 decibels lower than the foreground audio content.




Background sound that meets this requirement will be approximately four
times (4x) quieter than the foreground audio content.

Current wording for Best Practice Measures for Checkpoint 1.7

[None listed]


Proposed wording for Best Practice Measures for Guideline 1.7

Current wording for Benefits of Checkpoint 1.7

* Individuals with hearing impairments that limit their ability to hear
all of the frequencies of speech can make out the words from the sounds
they can hear because they are not mixed with residual sounds from the

Proposed wording for Who benefits from Checkpoint 1.7 (Informative)

*        People with hearing impairments that limit their ability to
hear speech at all frequencies are better able to recognize the main
audio content without interference from background noise.

*        People who do not have access to a text transcript can hear and
understand audio presentations.

*        People with attentional disorders that make it difficult for
them to pick out the important sounds in a noisy environment will be
better able to hear the difference between what is important and what is

*        People with limited knowledge of the language of the audio
content will find it easier to understand spoken material.

[js note: I took the liberty of adding some more examples]

Current wording for Examples of Checkpoint 1.7

* Example 1: a background image on a page.


A background image and text are arranged so that there is no image
behind the text or the image is so faint that the difference between the
darkest part of the image and the text (which is dark) meets the
standard foreground/background contrast requirements. The image behind
the text also does not contain lines that are about the same width as
the characters so they do not interfere with character recognition.


* Example 2: speech over background sounds.


Because speech is often naturally mixed with background sounds (movies,
live news etc) and cannot be easily removed or separated, captions are
provided (under checkpoint 1.2) to make dialog understandable. However
not all people can see or read the captions. Where speech is mixed or
recorded so that it is at least 20 db above any background sounds people
do not need to rely on captions to understand the dialog.

Proposed wording for Examples of Guideline 1.7 


*        [Example 1:Text over background image Moved to 1.6 [E2]

*        Example 1: speech over background sounds.


A video clip shows two people talking at a political meeting. In the
soundtrack, their dialog is clearly audible and understandable above the
buzz of other conversations in the background. 


[js note: I modified the example (a) to make it concrete and (b) to
eliminate the potentially confusing reference to captions. I also added
the example below]

*        Example 2. A Webcast of a live sporting event.

A football match is broadcast over the Web in real time.  The
commentators' description of the action is clearly audible against the
background cheers of the spectators.




"Good design is accessible design." 
Please note our new name and URL!
John Slatin, Ph.D.
Director, Accessibility Institute
University of Texas at Austin
FAC 248C
1 University Station G9600
Austin, TX 78712
ph 512-495-4288, f 512-495-4524
email jslatin@mail.utexas.edu
web http://www.utexas.edu/research/accessibility/


Received on Wednesday, 5 November 2003 14:00:12 GMT

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