Accessibility requirements for podcasting-related media

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Contents 1 Accessibility requirements for podcasting-related media 1.1 Transcripts 1.1.1 Format of transcripts 1.2 Captions (subtitles) 1.3 Audio description 1.4 Sign language interpretation 1.5 Alternative text for images 1.6 Web Content Accessibility Guidelines requirements

[edit] 1 Accessibility requirements for podcasting-related media

[edit] 1.1 Transcripts

Transcripts are text versions of the dialog and narrative of a video or audio file. They can include additional descriptive information, such as indication of music/noises/tone of voice etc if available.

Transcripts are primarily offered to provide access for deaf people but dyslexic people may also find it useful to read at the same time or after listening to the content. In addition transcripts may be useful for other people, e.g. who just prefer text to audio, or who don’t have time to listen to or watch a podcast.

A limitation of transcripts of video material is that it can be difficult to read a text document, either printed or on screen, at the same time as watching the video. There is no synchronisation between the two sources so it may be difficult to keep track of who is saying what about what. Also is it difficult to keep switching attention from one resource to the other.

[edit] 1.1.1 Format of transcripts

It is important that transcript documents are themselves accessible. PDF documents can be problematic for screenreader users, and even if they are prepared in an accessible way they may not be as easy to navigate as an RTF (Rich Text Format) document. RTF is the preferred format for transcripts, because it can convey structure, which may be lacking in plain text documents. In addition, RTF can be read by any word-processing program; it does not carry macro viruses; and it can be read by all Braille notetakers (some of which cannot read Word documents ³). The RTF document should include headings in order to convey structure to screenreader users.

There is currently debate about whether Microsoft Word would be the preferred format for transcripts as it may be easier to produce as part of the production process, and it is thought that this format can be opened by most word processing programs. This issue requires further research to find the preferred format for users and production processes.

Transcripts should have timestamps throughout so that the reader can find the relevant section of the video when needed. This is particularly important when an item on screen is being discussed or described in the dialogue or narration.

³ Access to Course Texts: Microsoft® Word or Rich Text Format?: http://kn.open.ac.uk/public/workspace.cfm?wpid=6214

[edit] 1.2 Captions (subtitles)

Captions are text versions of speech and other audible information in video. They are presented in the written language of the audio (as opposed to a translation). Captions are usually “closed”, i.e. they are encoded or invisible and must be decoded or made visible. Some captions are “open” and cannot be switched off ⁴. The advantage of captions is that they are synchronised with the video.

In the UK we often use the term ‘subtitles’ for captions, as well as for translation of foreign language.

⁴ Joe Clark’s Glossary: http://joeclark.org/access/resources/understanding.html

[edit] 1.3 Audio description

Audio description can be provided to support visually impaired people. It offers descriptions of the visual aspects of a video presented in audio. The descriptions are inserted into the pauses in the original audio. There are examples of videos with audio description on the RNIB web site ⁵.

When deciding whether descriptions are required it is necessary to consider how the original information is presented. For example, a geography video may show a particular geographical feature, but the narration may provide sufficient description and so additional audio description is not needed.

Mary Taylor provides guidance on describing figures in educational content and the issues in deciding whether descriptions are needed or appropriate, which can equally be applied to audio description for video ⁶.

⁵ Clips of Audio Description on TV: http://www.rnib.org.uk/xpedio/groups/public/documents/publicwebsite/public_adontvclips.hcsp

⁶ Guidelines for describing visual teaching material: http://kn.open.ac.uk/public/index.cfm?wpid=2709

[edit] 1.4 Sign language interpretation

The RNID notes that sign languages are as different to each other as spoken languages. Deaf people in different countries don't use the same sign language, although some sign languages do have a similar structure. Sign languages use a combination of handshapes and movements, facial expression, and shoulder movement ⁷.

British Sign Language (BSL) is the first or preferred language of over 50,000 people in the UK. It is syntactically and grammatically very different to English. There are technical issues with providing signing in an open format that can be viewed by everyone ⁸.

RNID notes that “Many hearing people think that with the presence of subtitles there is little need for sign language on television, without realising that sign language users are in fact being asked to access programmes in their second language.⁹"

⁷ Sign language (leaflet): http://www.rnid.org.uk/information_resources/factsheets/communication/factsheets_leaflets/sign_language.htm

⁸ Turning English material into BSL: http://www.ictrnid.org.uk/bslmat.html

⁹ Sign language on television: http://www.rnid.org.uk/howwehelp/research_and_technology/communication_and_broadcasting/signing_on_television/

[edit] 1.5 Alternative text for images

When images are used in album art or other information accompanying podcasts they may required alternative text. WebAIM’s article ‘Appropriate Use of Alternative Text’ ¹⁰ provides guidance on the content of this text. Alternative text should convey the function or purpose of an image, rather than describing the actual appearance of the image. Images that are purely decorative probably do not require alternative text. The alternative text of images that have embedded text should repeat that embedded text.

¹⁰ Appropriate Use of Alternative Text: http://www.webaim.org/techniques/alttext/

[edit] 1.6 Web Content Accessibility Guidelines requirements

Version 1 of the Web Content Accessibility Guidelines (WCAG) was published in 1999, and this was recently updated to Version 2.0. The Web Accessibility Initiative provides a summary of the changes between versions 1 and 2 ¹¹. The underlying principles are the same, but the structure and wording of the guidelines has changed. In addition some of the priorities have changed, particularly in relation to multimedia, as shown below. For universities who previously referred to WCAG version 1 it would be worth reviewing version 2 to see what changes may be required to web sites and multimedia.

For podcasts the relevant guideline from the Web Content Accessibility Guidelines (WCAG) version 2 ¹² is “Guideline 1.2 Time-based Media: Provide alternatives for time-based media” ¹³. For pre-recorded media this recommends the following:

Priority Level A:

• For video with no audio track:
  • Descriptive text transcript (including all relevant visual clues and indicators), or audio description

• For video with audio:
  • Captions

• Audio only:
  • Descriptive text transcript (including all relevant visual and auditory clues and indicators)

Priority Level AA:

• For video with audio, in which visual content is not conveyed in audio:
  • Audio descriptions

Priority Level AAA:

• For video with audio:
  • Sign Language interpretation

• For video with no space in the audio for audio description:
  • Alternative version of the video with pauses for audio descriptions

Above summaries are based on WebAIM’s WCAG 2.0 Checklist which emphasises that WCAG 2.0 guidelines should be referenced when determining conformance ¹⁴.

¹¹ How WCAG 2.0 Differs from WCAG 1.0: http://www.w3.org/WAI/WCAG20/from10/diff.php

¹² Web Content Accessibility Guidelines (WCAG) version 2: http://www.w3.org/TR/WCAG20/

¹³ WCAG 2.0 Guideline 1.2 Time-based Media: Provide alternatives for time-based media: http://www.w3.org/TR/WCAG20/#media-equiv

¹⁴ WebAIM’s WCAG 2.0 Checklist: http://www.webaim.org/standards/wcag/checklist

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