Propose new attribute for SSML to provide pronunciation or presentational hinting to AT

[alia11y]

At a recent APA meeting, ETS presented the use cases to propose new attribute for SSML to provide pronunciation to Assistive technology. I had created an issue #659 in aria and now moving it here.

Details: Currently, there is no standards-based mechanism for incorporating SSML into HTML to provide pronunciation or presentational hinting to assistive technologies which render text using text to speech synthesis (such as screen readers and read aloud tools). Across assessment vendors, a variety of approaches have been used to solve this problem, ranging from misuse of the WAI-ARIA standard, to creation of custom and data-attributes. Some of these approaches are problematic for braille users when hinted text intended for TTS is also rendered on the refreshable braille display. We propose for your consideration a new ARIA attribute tentatively 'ARIA-SSML' that utilizes JSON to encapsulate SSML functions, attributes, and values in manner that allows for easy consumption by Assistive Technologies.
Further details are available at : https://github.com/mhakkinen/SSMLinHTMLproposal

[LJWatson]

The use case presented for this attribute was pronunciation by screen readers, but I wonder if it also has a use case in applications that use things like the Web Speech API? Perhaps it is worth looking at an HTML (or other host language) extension instead of an ARIA attribute?

[jasonjgw]

The initially proposed use cases include provision of presentational hints and pronunciation to read-aloud tools used by people with dyslexia, which are often web applications that read the DOM directly. These cases can be addressed by standardizing a format for capturing SSML semantics in HTML.

However, screen reader support is likely to require an accessibility API mapping, coupled with suitable enhancements at the platform and screen reader layers. I agree that the proposed functionality is generally useful and not confined to "accessibility-related" scenarios.

[brennanyoung]

Seems to me that the existence of non-accessibility use cases should not preclude progress on an aria attribute such as aria-ssml especially because one of only two problems and limitations identified by the pronunciation task force regarding this proposed attribute is

aria-ssml is not a valid aria-* attribute.

Well... that's in the gift of this community. Shall we not take seriously efforts like https://github.com/alia11y/SSMLinHTMLproposal ?
If not now, then when? What are we waiting for?