Re: Captions for audio clips

To: GL List
From: Eric Hansen

Understandings

Based on the conversation regarding my earlier memo
(http://lists.w3.org/Archives/Public/w3c-wai-gl/1999OctDec/0185.html), my
understandings are as follows:

1. It is OK to refer to "captions" for virtually all audio presentations,
not just for auditory tracks of multimedia presentations. 

2. WCAG 1.0 does not specifically address captions for audio-only
presentations.

3. There is a need for a checkpoint that addresses captions for audio-only
presentations, i.e., to use Jason's term, "unimedia" audio presentations.
Suggested text: "1.4.A For any audio-only presentation, provide captions.
[Priority 2 {or 3}]"

4. There are differences of opinion regarding the proper priority for such a
checkpoint, though most seem to prefer Priority 2 or 3 as opposed to
Priority 1.
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Possible Taxonomy of Sounds

Taxonomy A
A. "Sounds" (or "auditory information", which seems a little ambiguous).

A.1. Audio presentations (requires captions) 
A.1.1. Audio-only presentations
A.1.2. Auditory tracks of multimedia presentations

A.2. Sounds with short single-segment text equivalents (e.g., a signal or
alert rather than as a multi-segment message)

====
Question About Captions for Short Single-Segment Audio-Only Presentations

Should captions be considered relevant for short single-segment sounds such
as beeps, clicks, etc.? The answer hinges on the definition of
synchronization. Of course, they require a text equivalent, but if the sound
is short and has only one short message segment, then should the
simultaneous presentation of the text and the sound be called
synchronization? The answer to this question affects the definition of
captions:

"Captions"

"A text transcript that is synchronized with its audio presentation. The
term "captions" applies to both auditory tracks of multimedia presentations
(movie or animation) and other audio presentations (standalone audio clips,
streaming audio, other sounds, etc.)."

{OR}

"Captions"

"A text transcript that is synchronized with its audio presentation. The
term "captions" applies to both auditory tracks of multimedia presentations
(movie or animation) and other audio presentations (standalone audio clips,
streaming audio, etc.), except for short sounds with brief single-segment
text equivalents (such as beeps and click-sounds)." 

I think that the second option is more in keeping with WCAG 1.0 and may be
better for others reasons as well.

====
Revised Definition of Text Transcript: Two Options

Following are suggestions.

"Text transcript"

"A text equivalent of the audio presentation. A text transcript is sometimes
called 'caption text'."

{OR}

"Text transcript"

"A text equivalent of the audio presentation or other sound. A text
transcript is sometimes called 'caption text'."

Suggestions welcome.
====

Received on Monday, 13 December 1999 17:18:48 UTC