RE: Question about 1.2.4 Captions (Live) (AA) and 1.2.9 Audio-only (Live) (AAA)

There’s a larger question here that we’ll probably need to address at some stage as to the circumstances in which automatic captioning tools, image description tools, etc., can serve to satisfy WCAG success criteria. There are two cases that seem important to distinguish.
Case 1: use of the tools by authors for preparation of content. I expect this to be uncontroversial, as the authors can review the output of the speech recognition or image recognition software and correct it before publishing WCAG-conformant content to the Web.
Case 2: use of the tools to add captions or descriptions to content without any possibility of authorial intervention to correct mistakes. Examples of this usage would include automatic captioning of live audio tracks in synchronized media, or automatic construction of text alternatives for large collections of images.
Given recent advances in deep neural networks, we may eventually reach the point at which case 2 (at least under confined circumstances) can constitute a sufficient technique for meeting the relevant success criteria.

From: David MacDonald []
Sent: Sunday, July 16, 2017 5:12 PM
To: Patrick H. Lauke <>
Cc: WCAG <>
Subject: Re: Question about 1.2.4 Captions (Live) (AA) and 1.2.9 Audio-only (Live) (AAA)

>> My understanding here is that since it's about captions, and synchronized media, this does not apply to audio-only (live) content.

It would be tough to get consensus from stakeholders on this... an interesting problem. The stakeholders this would affect most might be radio stations. In this case the internet is a broadcasting medium and the page is being used in a way different from how we would have conceived in the early 2000s when most of WCAG 2 was written. Certainly at the time we could not have gotten consensus to require stations to hire a full time captioning service. I expect there would be a lot of claims of undue burden.

I think we'll be facing some sever opposition if we make such a huge increase in requirements in a dot version. In 5 years or so automatic captioning might make this a lot less of a burden. I'd punt it and add it to the Silver wish list.

David MacDonald

CanAdapt Solutions Inc.

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On Sat, Jul 15, 2017 at 9:55 AM, Patrick H. Lauke <<>> wrote:
I would guess the cleanest change to address this would be to to promote 1.2.9 from AAA to AA (technically, if live audio as part of multimedia/sync'd media/video presentation needs to have captions, then so should audio-only - captions or some other form of alternative - as the effort required would be same or arguably even lower than injecting captions into multimedia/video).



On 11/07/2017 15:42, Patrick H. Lauke wrote:
On 11/07/2017 15:07, Andrew Kirkpatrick wrote:
I don’t remember the conversation around this specifically, but I do recall there being a lot of concern even about live captions for synchronized media at AA, so this may have been a compromise.

I can vaguely recall discussion (but may be misremembering) around the volume of audio content that online radio stations and other continuous broadcasters put out, so it may have been done in response to comments. I do see that 1.2.9 was added between CR and PR, but don’t see anything in a quick scan of the minutes.

Thanks Andrew. Wondering if this is something that could/should be looked at for WCAG 2.1. Currently, this seems weirdly unbalanced - and as the volume of sync'd media, even just live videos with audio, is becoming more and more common (while at the time of WCAG 2 it may have been more of a rarity?) this will probably start to cause issues or result in weird loopholes. (For instance, if faced with decision of whether to just stream audio or do an audio+video stream, some developers/publishers may opt to just to audio-only since that then has no captioning/alternative requirement under AA - and yes, while 1.1.1 does have a tiny mention about live audio, "text alternatives at least provide descriptive identification of the non-text content" means that all that would be required to pass here too is a simple "there's some live audio here..." type short description).


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Received on Monday, 17 July 2017 14:22:52 UTC