In December 2010, WebAIM (Web Accessibility in Mind) conducted a survey of preferences of screen reader users. WebAIM reported these results:

The conclusion identified in the previous screen reader user surveys remains: there is no typical screen reader user. These results highlight significant changes and trends over a span of only 2 years, results that we hope will drive informed web accessibility practices.

A few items of note:

• JAWS is still the primary screen reader, but usage is decreasing as usage of NVDA and VoiceOver significantly increases.
• The perception of free or low-cost screen readers is improving.
• 98.4% of respondents had JavaScript enabled.
• The outlook for future web accessibility is optimistic.
• Two-thirds of the respondents use a screen reader on a mobile device, up from only 12% two years ago.
• Most respondents find longdesc useful.

For details, see Screen Reader User Survey #3 Results.