Accessible Podcasts and Vodcasts

In July 2006, I was fortunate enough to be asked to podcast several sessions at a conference I was attending.  It was just three years ago, but podcasting was still something so new and exciting in many fields of technology that it was considerably on the bleeding edge.  Today, the techniques and tools we used then would be considered rudimentary and unnecessarily old-school. 

Now the sleeker tools are available to more and more people.  And what do we have?  More than 100,000 podcasts are hosted on iTunes, and countless numbers more than that are hosted all across the web.  With quick and easy publishing tools, it's easy to create content and even easier to distribute it.  Before you know it, you can have a ton of subscribers (almost as many as you have followers on Twitter).

Podcasts and vodcasts are an example of a very popular and widely-used form of time-based media that is published on the web.  Time-based media content is perceived as more of a challenge to make accessible than text content, for the obvious reason that the usual tools for accessibility (screen readers, magnifiers, skip blocks, etc) do not readily apply.  It often seems at first that these pieces of content are doomed to be unreachable by some users.  This is not the case at all.

The WCAG 2.0  Guideline that relates states that "alternatives for time-based media" must be supplied.  Broken down for audio, video, and audio/video, the suggested techniques are as follows:

Audio-Only Content

• If your content is just audio, all you need to start is a textual transcript.  This transcript will basically act as a longdesc description of the audio content, but does not have to be marked up using this attribute.  Not all browsers or accessibility tools support longdesc, so a better bet is to either:
  • include it on the page directly adjacent to the audio content ONLY IF the audio content is short (ie, the lyrics to a song can go right with a song)
  • include a link to the textual transcript.  make sure that the link is placed immediately after the audio content on the page so it makes sense to a user with a screen reader.
• Be sure to mention in or close to the audio content's header, that a textual transcript of the audio follows.
• It's important to note that the textual transcript must transcribe not just dialog but also important background noises.  Descriptions of important implied actions must also be provided.  To get a feel for what should be included, read some Golden Age Radio transcripts and pay attention to the "FX" and "Narrator" content related in there.
• In live streaming audio, it's a bonus to include a note during the streaming that an audio transcript is on the way when the event is over.

Video-Only Content

• For video-only content, the same techniques for providing a transcript of audio content will be a sufficient measure.  The transcript is bound to be lengthier, as the non-dialog descriptions will likely need to be longer with more unspoken data presented.
• Another sufficient technique is to publish an audio track of a spoken transcription of the video content.  Make sure that the audio track is
  • linked directly adjacent to the video content
  • labeled as an alternative to the video content
  • in a web-common format like mp3 or wav (mp3 works better for compression in most cases)
    Also, if there is no audio in your video, be sure to include a "no audio in this clip" note somewhere close to the video.  This is a courtesy to keep users from having to reach behind their monitor and try to figure out if their speakers are turned off.
• For live streaming video content, try to link to a textual equivalent if possible, ie the graduating class's web page during a graduation ceremony, or a news channel's article page for a piece of streaming video related to a story.

Synchronized Media Content

• For video content with audio (synchronized media), things get a little trickier. There are two related guidelines here.  One states that the developer must provide captions, either open- or closed- when the synced media is not labeled and acting as a media alternative to text-based content.  Another states that an audio description should be provided for the video content of the synced media.
• Here are some notes to keep in mind for including captions:
  • Open captions are text captions put directly into the media content that the user cannot turn off.  Almost any current video editing program makes it possible to include these in your vodcasts, but it does take some engineering on your end.  Plus the captions can be intrusive to users who do not use them.
  • Closed captions are text captions with a display controlled by the user.  Users can turn these on or off.  Youtube has now made it easy to add captions to your videos (Do it!).  Many media players have a capacity for supporting closed captions.  For more information, go to the WebAIM Web Captioning Overview.  If you use closed captioning for your podcasts, be sure to note it and provide instructions for turning the captions on and off.
  • As with textual transcripts of audio content, the captions are only complete if they include important noises, music, details of speech, and actions.
• For audio descriptions of the video, here are some things to remember:
  • place the link right next to the video (of course)
  • OR create a second audio track to the video that the user can select, including audio descriptions of important non-verbal details in pauses between dialog.
  • OR create a second movie with these audio descriptions where the action is paused as necessary to fit in all of the audio description.  Almost embarassingly, the commentary track on the DVD for "The Simpsons Movie" is actually one of the best examples I've seen of this.
  • Naturally, if you use either of these last two techniques, be sure to note close to the media that these alternatives are available.  Also be sure to label either of these alternatives as alternatives.

These guidelines should be followed for all audio and/or video media content except when that content is an alternative to text-based content.  If the media is acting as an alternative, it must be clearly labeled in a way that indicates this.

And as always, make sure that your media player's playback mechanism and volume are controllable by the user through the browser!  (If you use Drupal as your CMS, the SWFTools module is good for this.)