Issue #3870 discussed whether a caption track could be considered a valid alternative for audio-only media. The problem is that while captions technically are an alternative, currently user agents do not display cations when present in a track element when the audio fiIe is played via the native audio element (I hope I got this correctly - I haven't validated this in practice).
I picked up the task to check the 1.2.1 Understanding doc to see if any additions might be useful to cover this case.
There is a section of benefits of 1.2.1. All but the first of the benefits listed clearly imply that the text alternative is visible. Use cases such as reading to understand better (for people with cognitive issues) or reading with braille (blind users not relying on audio) also seem to imply that the text is not timed as in a synchronized caption track.
"Situation A: If the content is prerecorded audio-only" lists only one Sufficient Technique G158 that describes the provision on an (untimed) transcript as text on the page to be consumed in whatever way. The example is a podcast transcript.
To cover the case raised in issue #3870 one could think of adding a note to the 1.2.1 Understanding text at the end of the section Intent (I just draft something here:)
Note
Until there is sufficent accessibility support in User Agents for visually displaying captions provided in a track element as an alternative to audio files, the provision of a timed text alternative in a track element does not meet this Success Criterion.
Issue #3870 discussed whether a caption track could be considered a valid alternative for audio-only media. The problem is that while captions technically are an alternative, currently user agents do not display cations when present in a
trackelement when the audio fiIe is played via the nativeaudioelement (I hope I got this correctly - I haven't validated this in practice). I picked up the task to check the 1.2.1 Understanding doc to see if any additions might be useful to cover this case.There is a section of benefits of 1.2.1. All but the first of the benefits listed clearly imply that the text alternative is visible. Use cases such as reading to understand better (for people with cognitive issues) or reading with braille (blind users not relying on audio) also seem to imply that the text is not timed as in a synchronized caption track.
"Situation A: If the content is prerecorded audio-only" lists only one Sufficient Technique G158 that describes the provision on an (untimed) transcript as text on the page to be consumed in whatever way. The example is a podcast transcript.
To cover the case raised in issue #3870 one could think of adding a note to the 1.2.1 Understanding text at the end of the section Intent (I just draft something here:)