Hearing the call
Linux solutions to help the visually impaired use computers
Summary
Joe Barr examines voice interfaces, screen enlargement software,
and other Linux-compatible ways the visually impaired can use
computers. (1,200 words)
By Joe Barr
I used to work with a very bright fellow named James Violette. Not long
after I started writing for LinuxWorld, James suggested a book to me
called Virus Of The Mind, written by Richard Brodie. I liked it so much that
I did a column about it (see Resources). Violette and I have both moved on
from the positions we held then, but we still stay in touch by email. In a
recent message, Violette described a presentation he had seen about Linux
for the blind and visually impaired. He said he thought it might interest
me. He was right.
Violette is an enthusiastic individual. His enthusiasm sold me on the notion
of memes about a year ago, and he was just as pumped up this time about the
presentation he had seen at the Air Capital LUG in Wichita, Kansas (see
Resources for a link to ACLUG). Matt Campbell had demonstrated a variety of
ways to make Linux accessible to the visually impaired. It was hard to tell
if my friend was more excited about Campbell's message or by Campbell as a
person, but there was no mistaking that Violette was enthused.
Matthew Campbell is a 19-year-old computer science major who has just
completed his freshman year at Wichita State University. He has been using
Linux for about four years and, while not attending classes, holds down a
part-time job writing Java and C code. Just before Independence Day,
Campbell gave a presentation to the ACLUG on Linux for the blind and
visually impaired, which included the use of speech synthesizers.
As is the usually the case with Linux software, there are a number of tools
with which the visually impaired use Linux. Campbell's eyesight is good
enough to read an 80 by 25 character display if he gets very close to the
screen. Campbell told me that he can also work with a GUI, with a resolution
of up to 800 by 600 pixels on a 17-inch monitor and 1,024 by 768 pixels on a
20-inch monitor; he has a 17-inch monitor at home and a 20-inch at work. But
for many others, reading from the screen is not an option, no matter how
close to it they get.
Solutions in sight
People like Campbell, who can see but not see very well, can use screen
enlargement software to magnify text on a portion of the screen. But as
Campbell explained in his presentation, with Linux you can accomplish
something very similar by adjusting the settings for virtual display size in
the XF86Config file. For example, setting the physical screen size to 640 by
480 pixels while defining a virtual screen as being 1,024 by 678 pixels
allows you to scroll around over a magnified screen.
Hardware options also exist for visually impaired Linux users, but they are
expensive. Braille devices can cost thousands of dollars and hardware
synthesizers several hundred. There is also the software approach, which
includes speech synthesizers. Also called TTS (text-to-speech) programs,
such software reads aloud text input from a screen reader. There are speech
synthesizers available for both Windows and Linux, but whereas they cost
several hundred dollars for Windows, there are several free (both as in beer
and speech) products available for Linux.
If you ever find yourself wondering about the strength of the Linux
community, consider what Campbell has done. He demonstrated the speech
synthesizers to ACLUG after consulting with a blind friend on the Internet.
She was frustrated with the cheap ($200 to $300) product she was using on
Windows. Because Campbell doesn't use speech synthesizers himself, he had to
become more accomplished with Emacs and Emacspeak (more on which in a
moment) in order to help his friend install and use the synthesizers. And
Campbell did all this after helping her install and learn Linux well enough
to get started.
Emacspeak is a highly regarded speech interface for visually impaired users
that is covered under the GPL. Now in its Golden Dog (version 12.0) release,
Emacspeak works with speech synthesizers like IBM's ViaVoice to translate
the Emacs interface into voice.
Using Emacs, visually impaired computer users can browse the Net; send and
receive email; write, compile, and debug software; and do just about any
other console function you can imagine. As Campbell notes on his Website,
"Using Emacs and Emacspeak, blind users gain access to Unix-like systems."
(See Resources for a link to Campbell's site.)
Other options
Naturally, Emacspeak is not the only game in town. The CSTR (Centre for
Speech Technology Research) at the University of Edinburgh, Scotland, is
home to the Festival project, which also provides a viable option (see
Resources for a link). Festival is a multilingual speech synthesis program
written in C++ and Scheme. The latest version (1.4.1) was released in
December of 1999 and is available free for unrestricted use.
Alan W. Black, Paul Taylor, and Richard Caley are the primary authors of
Festival. In the academic tradition of standing on the shoulders of those
who came before, they built Festival on the Edinburgh Speech Tools Library,
and used a speech synthesizer written in 1995 by Amy Isard as a model. The
code, however, is all new.
Speakup is another tool available to Linux users to hear text written to the
console (see Resources for a link). Speakup is actually a number of kernel
patches, compatible with 2.2.7 and above of the stable kernel tree and
2.3/2.4x of the development tree. The advantage of working in kernel space
is increased performance, but not everyone feels at ease modifying the
kernel code. Just as Emacspeak uses the W3 browser, Speakup uses Lynx.
Which is the best solution for Linux? According to Campbell, it depends.
Emacspeak is great, but there are limitations. Campbell's Internet friend
uses both Speakup and Emacspeak, depending on what she is doing. It seems
that Speakup is better for some specific tasks, so she has that installed on
one machine and Emacspeak on another.
One thing that holds back Speakup is that the kernel image you build to
include Speakup only works with the specific voice synthesizer for which you
build it. Campbell feels that Speakup will not be included in major Linux
distributions until it can support synthesizers dynamically.
Campbell told me that although Linux offers free, powerful tools for
accessibility, it has not matched the software available for Windows -- or
hasn't yet, at least. Screen readers, the programs that read the contents of
a screen and then pass the text off to a speech synthesizer or Braille
device, exist in the Linux world, but they work only in console mode. For
Windows, there are screen readers that can grab text from a GUI.
At the ripe old age of 19, Campbell has already managed to neatly package
Emacspeak in RPM format and create his own Linux distribution called
ZipSpeak (based on the ZipSlack distribution), which includes Speakup. He
has also created a series of demos for blind newbies and has been
interviewed on an Internet talk radio show called Hanitalk with Kirk Reiser,
who is the main programmer for Speakup. And he has infected James Violette
and myself with his quiet, positive, can-do attitude.
I'm not going to be surprised when I learn one day that Campbell has been
involved with a project that brings Linux screen readers up to par with
their Windows cousins, one that finally makes them capable of reading text
from X just as Windows programs do from the Windows GUI. [Image]
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About the author
Joe Barr is a contributing editor at LinuxWorld and a recovering
programmer. In addition to writing for LinuxWorld and The
[Image]Dweebspeak Primer, he is currently working with Nicholas Petreley
on a Linux documentation project called
The Essential Linux Open Book. Visit Joe's Desktop Linux discussion
in the new Linux Forum, hosted on ITworld.com.
Resources
* "The Memes They Are A-changin'," Joe Barr (LinuxWorld, May 1999):
http://www.linuxworld.com/linuxworld/lw-1999-05/lw-05-vcontrol.html
* Air Capital LUG homepage:
http://www.aclug.org/
* Speakup homepage:
http://www.linux-speakup.org/
* Emacspeak homepage:
http://emacspeak.sourceforge.net
* Emacspeak HOWTO:
http://www.mv.com/ipusers/vanzandt/Emacspeak-HOWTO.html
* Matthew Campbell's homepage:
http://www.crosswinds.net/~mattcamp/
* The Festival Project:
http://www.cstr.ed.ac.uk/projects/festival/
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Last modified: Wednesday, July 12, 2000
