Screen reader

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A screen reader ( English screen reader "Screen Reader"), and read-aloud application called a is software that blind and visually impaired an alternative user interface instead of text mode or instead of a graphical user interface provides. A screen reader conveys the information that is usually displayed on the screen using non- visual output devices. The control elements and texts are usually reproduced acoustically by means of speech synthesis via a sound card or tactile via a Braille display.

The output is not limited to text: all graphic elements shown on the screen such as windows , menus , selection boxes , current input position, symbols , etc. are displayed . The detail of the display of these elements can usually be set individually. This means that not only individual programs but also the entire graphical user interface can be operated by the blind and visually impaired via voice output and Braille display.

Some screen readers are limited to specific applications and do not allow access to the operating system. The screen readers are mostly operated exclusively with the keyboard .

Screen readers enable u. a. also reading and operating websites . In the case of visual content ( graphics , animations , videos ), the alternative texts are read out. With special key combinations z. B. can be jumped from heading to heading (usually with the H key) and from paragraph to paragraph (usually with the P key). Direct control of other text structures is also possible. However, the requirement is the barrier-free design of a website .

Speech output

The generation of the synthetic speech in order to output the information acoustically takes place according to two different methods, depending on the manufacturer:

On the one hand there is an external device which is connected to the PC and which generates the speech independently of the computer used. This only has to supply the output medium with the information to be read out.

On the other hand, there is the simpler option of producing the synthetic speech with a program (which many screen readers have integrated) and then playing it back over PC speakers or headphones.

Since the synthetic speech is produced by a machine, the speech output does not always appear pleasant and harmonious, as the sentences are read out monotonously without pause or stress and not every word is pronounced correctly. In most cases, a remedy is provided by a dictionary function built into the software, with which the user can initiate a special pronunciation for certain words, terms, names and character strings (e.g. smileys, abbreviations) in order to make them easier to understand. The user can decide for himself whether a male or female voice should sound; He can also set whether the text should be spoken slowly or quickly.

Well-known screen readers

Free or open source


  • JAWS , short for job access with speech . The most famous screen reader, but very expensive at 2,000 to 3,000 euros.
  • COBRA - German screen reader from BAUM Retec AG . Joint successor to BLINDOWS and VIRGO.
  • Blindows - German screen reader from FRANK AudioData, later AudioData GmbH (today BAUM Retec AG ) for Windows 3.11 to Windows XP. The development of BLINDOWS was stopped in 2006 in favor of COBRA.
  • Virgo - German screen reader from BAUM Retec AG for Windows 3.1 to Windows XP. The development was stopped in 2006 in favor of COBRA.
  • SuperNova , formerly HAL from Dolphin
  • System Access
  • Window eyes

Part of the operating system

Browser plugins for screen readers

  • ChromeVox for Google Chrome
  • FireVox for Mozilla Firefox. Last updated August 2008.
  • Webformator for Internet Explorer. Last version 2.4c from July 9, 2009.

Web links