http://www.sitepoint.com/article/ajax-screenreaders-work

Chalk and cheese. Oil and water. For all the recent talk about AJAX, no one has fully explored whether these analogies can justly be applied to the combination of AJAX and screenreaders ... until now. In this insightful report, James reveals the results of independent tests he has conducted using AJAX scripts in a variety of screen reader software. The results are sure to surprise you!