What constitutes a change of content in a live region?

Wise ones!
I have a conundrum for thee.
I have recently been working on prototypes for accessible real-time
validation of password strength indicators.
Usually these are presented as a series of images or icons that change
when the value in the input field passes a test.
To make this accessible, we played around with updating the image's
accessible name (provided via its alt text, aria-label or title) and
put the image in a live region to ensure the change in the name is
announced to screen reader users.
You can see a simplified prototype of the idea (using images
presenting traffic lights and alt text indicating the traffic light
colors)at:
http://a11yideas.com/testcode/alttextliveregions/testAltTextLiveRegions_v2.html

When you hit the button, the images change along with the accessible
name source of your choosing. The change should be automatically
announced by screen readers. Or should they?
NVDA (with FF and IE) and Voiceover (iOS 9.1) announce the updated
accessible name regardless of the method (alt, aria-label, or title)
used to provide it.
Jaws does not announce the change.
The big picture question:
Should changes in the accessible name of a widget located inside a
live region, be interpreted as a change in the live region content.

I tried looking around the ARIA spec, and I did not see a definitive
answer to this question.
If there is a clear answer to this, feel free to point me to it (I may
have missed it).
If the standards documentation does not address this explicitly, I
think a future version should.

It is a reasonable approach for these types of problems, and it would
be good to know whether the lack of uniform support for them should be
considered a limitation of certain assistive technologies, or whether
this is simply not an acceptable approach.
Thanks
-Birkir

Received on Wednesday, 4 November 2015 01:53:33 UTC