My HTML page contains the following line:
<abbr title="World Wide Web Consortium">W3C</abbr>
When reading the page with NVDA screen reader (version 2016.1) it only read "W3C" but never the title.
I tried to find a setting in NVDA to activate the reading of the title attribute but without any luck. Nothing also on Google about this limitation (last version of NVDA should read titles).
I have not tried with any other screen readers like JAWS or Voice Over.
Blind people understand abbreviations like other people. So they do not want to hear the definition of FBI, NASA, W3C each time those abbreviations are spoken. (although this can be configured in some screen readers)
If you think that an abbreviation should be explained, then everyone is concerned, and providing a definition with an abbr tag is a bad idea, because it requires a standard user to hover the term with a mouse.
In fact, the only interest of the abbr tag is to mark semantically an abbeviation, in order to be spell-out for instance. If you want to explain an abbreviation use full definitions.
Bad example:
<abbr title="Doctor">Dr</abbr> Martin lives in Lincoln <abbr title="Drive">Dr</abbr>
He works for the <abbr title="Worldwide Web Consortium">W3C</abbr>Good example:
Doctor Martin lives in Lincoln Drive
He works for the World Wide Web Consortium (known as the <abbr>W3C</abbr>)