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Linux accessibility for people with vision impairment

by Sean Murphy

In the early 1980's the personal computers (PCs) were introduced into the consumer market. These computers were used by people to play games, run small business applications; students used them for their studies, and all manner of tasks. Even people with vision impairment managed to join in the new revolution.

A screen reader is a program mainly used by people who are blind, partially-sighted or have dyslexia to enable them to access computers. In simple terms, a screen reader consists of two parts; the speech synthesiser which produces audible speech and the screen reader software itself which sends the appropriate information from the visual PC screen to the synthesiser.

The first screen reader was developed for the Apple IIE and IBM PC's computers in the early 1980's. These programs work in a pure text environment, not like today's GUI (Graphical User Interface) environments. The introduction of the text based screen reader opened new job and recreation opportunities for people with vision impairment.

In the early 1990s GUI was introduced into the market. This environment prevented people with vision impairment from using computers due to their purely graphic nature. The Apple Mac was one of the first computers to have a GUI operating system. Soon after Microsoft introduced their version of the GUI operating system. The days of text based applications were numbered. Screen reader companies saw the new change in the market and started to develop products for the new GUI environments.

Early in the 1990s Linux was also introduced into the computer world. This new operating system was based upon UNIX and was (still is) free. This new concept of not buying the operating system was new to the computer world. More important, the source code was freely available. Linux was quickly adopted by the technically minded end-user who saw huge potential with this operating system.

People with vision impairment who wished to use Linux or UNIX used an MS-DOS computer with a Telnet program via a serial cable. They could access any text based application via this method under Linux. The cost of using Linux was quite high because they had to purchase two computers.

In the mid 1990s the first screen reader was develop for the Linux operating system called "Emacspeak". Now People with vision impairment could use a computer with Linux installed on it. Emacspeak was developed within a Linux text based application called Emacs. T. V. Raman was the founder of Emacspeak. This screen reader is still a very powerful application due to the powerful nature of the Emac's application. A majority of the tasks which were performed under Linux could be performed within Emacs. Such as: writing documents, spreadsheets, managing networks and servers, text based browsing, etc. People with vision impairment had to work within the Emac's environment. They still did not have access to the Linux virtual terminal or the start-up messages of the operating system.

In the late 1990s, a new screen reader called "Speakup" was developed by Kirk Reiser and Andy Berdan which provided people with vision impairment access to the virtual terminal and start-up messages. Now people with vision impairment were able to run Linux text based applications which were not specifically designed for Emacs. This was a major step forward in the Linux accessibility world.

"BrlTTY" developed by Nicolas Pitre, Dave Mielke and Stéphane Doyon was released in the mid to late 1990s. This screen reader, or more correctly a Braille Console application, was another revolution to Linux. For the first time, Braille output was possible on a Linux computer instead of speech. Braille is the alternative to printed material for people who are blind. The Braille is produced on a Braille Refreshable Display. The price of a Braille Refreshable Display starts at $6,500.00 up to $20,000.00. As you can see from the price of this specialised hardware, not many people with vision impairment can afford to buy a Braille Refreshable Display. The BrlTTY works with the Linux Virtual Terminal and majority of text based applications work with this program.

The text environment under Linux is still heavily used by a majority of Linux users. As with all modern operating systems, Linux does have a GUI (graphical) environment called XWindows. XWindows works on the Linux and Unix operating system platforms. This environment was not accessible to anyone with vision impairment whom relied on speech or Braille.

Only recently IBM and Sun have started to develop screen readers for the XWindow GUI environment. These programs are still fairly new and are not as feature rich as the Windows screen readers. In the last 12 months, the two XWindows screen readers have made major leaps forward. The programs in which they currently work with are: Open Office, FireFox web browser, Evolution email client and other applications which use the internal accessibility tools available within XWindows. The IBM screen reader is called "LSR" and the Sun screen reader is called "Orca".

Thus far I have mentioned some of the available screen readers. I have neglected to mention available synthesizes. A synthesizer is software or hardware which converts text into synthetic speech. People with vision impairment use the speech to know what is occurring on the screen. There is a range of free and commercial synthesizes available under Linux. Such as "DECTalk", "Eloquence", and "Festival". The screen reader sends the text to the synthesizes for the synthetic speech to be generated.

I must point out; all the people and companies who have done the development of the screen readers have done the work in their own time and have freely given the product to the disability community. I shall take this time to thank all these people for their hard work to make Linux as accessible as it is today.

The Ubuntu Linux Distribution comes with Orca and Speakup as part of the operating system with a free software synthesizer by default. Other people in the Linux community have included Speakup as part of other Linux distributions.

About the author

Sean is an experienced computer user and developer, currently working as a Network Support Engineer Manager for a small networking solution company called SkyBridge. He is blind and has been using a range of screen readers for the last 25+ years. Sean has been assisting web and application developers in user testing for accessibility for the last 12 years.

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Page last updated 13 January 2010.