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NVDA Free Open Source Screen Reader For Windows Reviewed

30 September, 2007 by Peter Verhoeven

Good news for those who can not pay the price of a commercial screen reader like Jaws, Window-Eyes or Hal. Also good news for those who want access to any computer on any place, because NVDA can run from any USB stick. NVDA is a free open source screen reader for Windows XP and Vista.

NVDA allows the user to find out what is happening on the screen, by querying the operating system and using a speech synthesizer to output the information.

I several times asked Dolphin why Hal and Supernova does not support the Firefox web browser. Is it realy so difficult to let a screen reader work with this popular web browser?

Those working on the open source NVDA screen reader, do not recommend using Internet Explorer. No, they are recommending Firefox and it realy works great! With NVDA you can simply read a web page in Firefox by cursoring through the page, or press insert + cursor down to automatically read aloud the entire web page.

You can also use NVDA with Internet Exploer, but at this moment activating links while reading web pages sometimes fails, so Firefox is realy recommended.

NVDA gives you complete access to the Windows operating system by speech. The level of access is much the same than you know from commercial screen readers. Also applications like Microsoft Word, Microsoft Outlook, Outlook Express and Skype are made accessible and can be used without problems with NVDA.

Commercial screen readers install there own video drivers on your system, often causing a lot of problems. NVDA does not use any special video driver and can run from a USB stick.

By default NVDA comes with < a href="">eSpeak speech synthesizer. eSpeak by itself is also an open source project. Because eSpeak does not need installation of any driver, it can be installed on a USB stick.
eSpeak does not sound human and personaly I realy have difficult to understand it. eSpeak comes in different languages. The quality of the speech highly depends on local people improving the speech rules of their language. It was also better if by default the speech rate in NVDA was set much lower, than it is set now. If you start NVDA for the first time you hear eSpeak in English speaking very rapid to you and for a lot of people for whom english is not their native language it is difficult to work with.

But if you don't like eSpeak, on all Windows XP and Vista computers, there is always a SAPI5 voice available. NVDA supports all SAPI4 and SAPI5 speech synthesizers. You can select another speech synthesizer via the Synthesizer option in the Preferences menu.

NVDA Synthesizer Configuration Window

After you load NVDA the NVDA user interface shows you a menu and a quick start document with instructions to use NVDA.

The menu bar has three menus: NVDA, Prefrences and Help. The NVDA menu include the options revert to saved configuration, Save configuration and Exit. If you select save configuration, NVDA will use the current settings next time.

The Preferences menu include the menu items User interface, Synthesizer, Voice settings, Keyboard settings, Mouse settings Object presentation, Virtual buffers and Document formatting.

User interface let you change the language of the NVDA User interface. NVDA currently has been translated into 11 languages including: Brazilin Portuguese, Czech, Finnish, French, German, Hungarian, Italian, Portuguese, Slovak, Spanish, Swedish and Traditional Chinese.

NVDA English User Interface

By selecting the synthesizer option in the preference menu, you can switch to a SAPI4 or SAPI5 speech synthesizer, or use the default eSpeak speech synthesizer.

By selecting the Voice settings option in the Preference menu, you can change voice related settings like Voice, speech rate, Pitch, Volume, speak all punctuation, Raise pitch for capitals, Say cap before capitals and Beep before capitals.

NVDA Voice configuration windows

With the Voice listbox, you can change to another speech synthesizer. For example if you have more SAP5 speech synthesizers installed on your computer, you can select SAPI5 in the Synthesizer menu option and select a specific SAPI5 speech synthesizer in the Voice settings menu option.

By choosing SAPI5 in the Synthesizer menu, the default speech synthesizer of your system will be selected. It is a pity that there is no key combination to cycle through different voices at this moment..

By selecting the Keyboard settings option in the Synthesizer menu, you can change the so called modifier key and turn echo typing on and off for characters and words. By default "Speak typed characters" is on and "Speak typed words" is off.

The Mouse Settings option in the Prerence menu let you change options like Report mouse shape changes, Report object under mouse and play audio coordinates when mouse moves.

In the Mouse settings window we find some new features, that we didn't know from commercial screen readers. The Report object under mouse is also known as mouse echo and is not new. In NVDA enabling or disabling this feature seems to have no effect. While moving the mouse over the desktop nothing is spoken out. Also moving the mouse over the taskbar or system tray, does not result in speaking out the objects under the mouse.

But Report mouse shape changes, and play audio coordinates when mouse moves, are interesting innovations. By selecting the last one you hear by sound where the mouse cursor is. Is it at the left of the screen, you hear sound in the left speaker. If it is in the right area of the screen, you hear the sound in the right speaker. If it is anywhere in the center of the screen, you hear the sound in both speakers. If it is in the top of the screen the sound is high and if you move the mouse to the bottom of your screen the sounds become lower.

NVDA Object Presentation Windows

Also the Object presentation option in the Preference menu, has some nice options like: Report tooltips, Report help balloons, Report object shortcut keys, Report object presentation information, Report object group names , Say object state first and Beep on progress bar updates.

The last one is again innovative. If there is a progress bar on the screen you can hear by beeping that it is going from 0% to 100%. The tone of the beeping becomes higher. It sounds a bit like you fill a bottle with water. This feature is helpful while web pages are loading in a web browser.

The virtual buffers option in the Preference menu give you options to configure virtual buffers. Virtual buffers are for example used in web browsers to allow you cursoring through a web page and navigating to objects like links, graphics, tables and forms.

The Document formatting option in the Preference menu, let you configure if special document formatting information must be spoken to you like, Font name, font size, font attributes etc.

By selecting the Help menu on the NVDA menu bar, you can go to the NVDA Home page, NVDA wiki and to the NVDA about page.

Concluding we can say that NVDA realy is a great screen reader and for common computer tasks as good as commercial screen readers. The performance of NVDA is realy excelent. Supernova needs more than a minute to load on my Windows XP system. NVDA loads in some seconds. Also the performance of speech is much better than that of most commercial screen readers.

At this moment NVDA does only offer speech support, but support of braille refreshable displays is planned in the near future.

On the NVDA community page you can participate in the NVDA open source screen reader project, you can subscribe to a NVDA user list to share your experiences with other NVDA users and you can help to improve NVDA itself by becoming a developer or by helping to translate and document NVDA i other lanbuages.

NVDA is written in Python programming language. Because it is a open source project you can download the source code of NVDA and participate in the developement to improve it and add new features to it.

The latest offical release of NVDA was 0.5, but I recommend to download a later so called snapshot. Maybe these releases are less stable, but include the latest features. By the way NVDA never crashed my system and after a crash of NVDA itself I could always simply load it again.

There are two types of downloads a full install version and a zipped version. The zipped version only needs to be extracted to your computer or to a USB stick and you can start nvda.exe from the location you extracted it. The install version, needs an installation process on your system.

NVDA Project Home page:
On this page you find all information about this project, including links to more reviews and how to participate.

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