The American Foundation for the Blind recently evaluated two free screen readers in their tech lab at the request of the Royal National Institute of Blind People (RNIB) in the United Kingdom. The two screen readers were NonVisual Desktop Access (NVDA) and Thunder. These two screen readers work on Windows-based computers.
NVDA is a free open source screen reader that gives feedback with synthetic speech. It is compatible with Windows 7, XP and Vista operating systems. It is compatible with refreshable Braille displays as well. Since NVDA is an open source application, interested parties can contribute to the screen reader’s improvement and development. For the project AFB used NVDA version 2011.1. You can download it at the NVDA website and learn more about the screen reader.
Similarly, the Thunder Screen Reader is free, provides feedback via synthetic speech and is compatible with Windows 7, Windows XP and Vista Operating systems. The documentation makes no mention of being accessible with refreshable Braille displays and is not an open source screen reader. Thunder version 2.021 was used for the project. You can download Thunder and learn more about it at the Thunder website.
Thunder and NVDA were evaluated on several Windows XP and Windows 7 computers. Both screen readers were evaluated on several different categories of computer use, which include:
Amazon and Bookshare
UK National Rail Enquiries (Travel)
General Web Browsing
Thunder does not support Outlook but does support the Windows mail client on Windows Vista machines. However, this won’t be covered because the AFB lab doesn’t have any Windows Vista machines.
In Outlook Express Version 6, both screen readers were able to read, forward, reply and attach files to messages. In addition, they were both able to access menus. However, Thunder had problems with message composition. Thunder did not speak any of the form labels such as To, CC, subject and attach.
NVDA had no problem reading messages since the “n” key jumps to the body of the message. To read messages with Thunder, it was necessary to browse down the page with the arrow keys or use the browser search tool to find the body of the message.
Both screen readers performed similarly when using Microsoft Word 2003. However, NVDA did a better job handling format attribute changes. Thunder had trouble with format changes when reading a document.
As far as banking is concerned, both screen readers completed every banking task. However, NVDA was considerably faster to use.
Both screen readers functioned well on iTunes. This included navigating the interface, searching for and playing music and other media, using menus, creating play lists, and searching for and buying music in the iTunes store.
As far as Amazon and Bookshare were concerned, both screen readers performed well on each web site–though, NVDA performed better and more efficiently than Thunder. Thunder had trouble with filling out forms and navigating web pages. It also had trouble with search results on Bookshare.
On the UK National Rail web site, NVDA outperformed Thunder. Forms and table navigation were significant problems for Thunder. Both screen readers had problems when it came to searching for and purchasing a ticket, though.
NVDA handled web browsing tasks much more efficiently than Thunder. For instance, NVDA has 26 hot keys to quickly move to web page elements. NVDA also has an elements list that can handle headings, links and ARIA landmarks on a page. Thunder tried to fill in form data but the process wasn’t very efficient.
NVDA is a great screen reader and it’s not far behind Jaws and Window Eyes. As a matter of fact, The Texas Center for the Visually Impaired offers their computers with the NVDA software installed. For more information, refer to the Special Notices section of the Ziegler Magazine.
Credit should be given to these developers for developing these free screen reader alternatives for blind and visually impaired people and I hope they keep up the good work.