2001 Conference Proceedings
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HOW DOES A BLIND SWITCH USER WRITE? Orthographic output for
people with profound multiple disabilities
Paul Blenkhorn – University of Manchester Institute of
Paul Hawes - Sensory Software International
In the provision of access to computer systems, any one
disability has a tendency to make the access systems devised for
people with a different disability more difficult to use. Switch
operated input, although slow, does not present a huge barrier,
provided that you can see the screen. Similarly, many blind
people operate computers extremely effectively by touch-typing
with the aid of a speech synthesis system.
However, for someone with a double disability, trying to cope
simultaneously with a switch or voice input system while relying
entirely on speech feedback can be extremely confusing, and
success is rare.
A few years ago, I gave a paper (Communication Matters, 1994) on
people with multiple disabilities using AAC by means of different
combinations of adaptive software. Most of these solutions
depended on one disability or another being less profound.
Solutions for the intelligent totally blind switch user remain
partial at best. Most telling of all was the very small number of
success stories. Over 20 years working in the field of assistive
technology, I can only recount a handful of users who have been
able to use such systems effectively.
The no-compromise solution
In theory, one could use an on-screen keyboard with auditory
scanning to drive a standard word processor, with a screen reader
providing the speech feedback from the word processor. In
practice this does not work.
Firstly, such a system requires an enormous effort to learn
(remember, the user must find all the functions from memory) and
with the complexity of modern software, it is easy to get lost if
you cannot see the screen. Another difficulty arises from the
differing features and behaviour of various assistive systems,
and in their interaction with application programs. It is a
serious technical challenge to control a screen reader and an
application simultaneously with a switch input program.
The total compromise solution
The opposite approach is to write software that handles the whole
of the input and output of the computer in a single program; with
all the speech prompts built in, and unwanted complications kept
out. The advances in modern development tools make this a more
attractive option than in the past and a number of programs have
appeared over the years, including an abandoned project by the
The major problem with this is the absolute limitation that it
places on the capabilities of the system. You have one, and only
one application that you can ever use.
There is a clear need for systems that are easy to teach to
users, and yet provide a sensible level of functionality. A
middle way is to use an on-screen keyboard that supports auditory
scanning, and to use this with speech-enabled applications. In
this way, the user is presented with a manageable system from the
outset, but is not prevented from using additional applications
in the future.
In practice there are still many problems, such as conflicts
between the speech used in different programs, incomplete speech
output from talking software, and lack of functionality in
We had recently completed two separate projects; an advanced
on-screen keyboard and a talking word processor for use by young
blind typists. At this time we were dealing with three people
with complex and challenging problems arising from MS. This was
the perfect opportunity to modify both programs to ensure that
they could be operated together seamlessly.
Some case histories
It would be worth pausing for a while to look at some success
stories from the past.
Shirley lost both her hand function and vision due to MS, and she
used switch input and voice output even before personal computers
as we know them existed. She used a machine called a Microwriter,
which used a chord keyboard similar to that used on the
present-day BAT keyboard. The machine was modified with a
scanning circuit with lights and differently pitched beeps to
replace the keys. This was plugged into an early Votrax
synthesizer, which had to be disconnected to make way for the
printer when her document was finished. The system took her a
year to master, after which she used it to produce personal
correspondence and to become the secretary for a support
organisation for switch users.
Jonathan has cerebral palsy and is totally blind. He had no
literacy skills and no method of effective communication until
the age of about 15. He then learnt to use a scanning Microwriter
with speech like Shirley. Later, he was accepted for a college
course and needed to learn a system that would allow him to
operate WordStar on a PC. He learnt a new coded input system
based on the CID 2 switch code. This uses two switches that are
held down while a counted number of beeps are sounded. For
example, holding the left switch for one beep and the right
switch for two may enter a letter on this system. This system was
transparent to the PC, and allowed the Hal screen reader and one
of the many simplified WordStar clones that were then in use to
Jonathan now lives in his own flat.
Mark was profoundly deaf and totally blind. He had no speech and
severe physical impairments.
His communication system consisted of a portable computer, a
Morse key and a vibrator placed against his neck. He would
communicate to other people by entering the Morse code. The text
could then be read on the computer screen. To talk back, you
typed a message on the keyboard, and it was tapped out in Morse
code on Mark’s neck by the vibrator.
There are more, but not a great many more. It must be obvious
that people like Shirley, Jonathan and Mark possess a degree of
determination that is not given to many. The challenge of
mastering such systems is great.
As explained in the introduction, we were anxious to produce a
solution that would be easier to learn, but that would also
provide a reasonable degree of functionality to the user. Whilst
completing the software, we worked with some users, addressing
the practical problems as they occurred. The talking word
processor needed to be controlled entirely by the on-screen
keyboard, and the speech feedback needed to be total.
Getting the features in the programs right was only a part of
the task. It was equally important to work out the methodology
that would work effectively for people.
Getting adequate speech support
AllWrite is a talking word processor that was originally written
specifically to help blind children to learn typing and literacy
skills. Using Word and a full feature screen reader is a tall
order for any blind newcomer to computers. Although there are
plenty of educational word processors with speech output, they
are all aimed at reinforcing literacy, and do not allow the
detailed interaction between speech and text that a blind user
needs. Talking cursor and editing keys are needed, along with
talking menus and – most importantly – the option to
use a high quality text to speech program. AllWrite has these
features, and can be used with DECtalk. DECtalk is ideal as it is
not only highly intelligible, but is very fast in its response.
(Technical note: we do not use the SAPI version)
Grids suitable for auditory scanning
HandsOff is an advanced on-screen keyboard with many customisable
features that allow it to be configured to both the user and the
application program being run.
The first task is to provide auditory scanning. Typically, this
has meant laboriously scanning the alphabet a letter at a time.
However, using a suitable grid layout, row/column scanning can be
used by auditory scanners. The grid is made with the vowels at
the beginning of each line, thus:
A a b c d E e f g h I i j k l m n O o p q r s t U u v w x y z As
the rows scan, the speech says "A row, E row, etc. It is easy for
people to remember after which vowel the letter they want occurs.
When the row is selected, it reads that part of the alphabet in
order. The locations on the right hand end of the short rows were
used for a few other common characters, such as space, enter and
When the user has become thoroughly accustomed to the layout, a
change is made to the grid settings, so that the initial letters
are replaced by word prediction.
A separate grid handles the main commands needed to operate
AllWrite. Again, intelligent use is made of the row/column
FILE new open save print EDIT cut copy paste undo bold underline
ARROWS up down left right home end READ letter word to cursor
line sentence document
Getting the right switch methods
As well as getting the grids right, it is also important to have
sophisticated switch operation. A blind user cannot watch the
scan, and so finds it much harder to anticipate a coming switch
press. As a result, overruns and missed scans are common unless a
very low scan rate is adopted. HandsOff allows the user to
reverse the direction of the scan at any time, allowing the scan
rate to be higher. You can even have a slower rate when scanning
Nonetheless, not every user will manage to use scanning, and a
two-switch method is also available.
The coded option
Coded input does away with the need for auditory scanning, and
allows the more able switch user to enter text far more
The attraction of Morse code is that it is very adaptable for
switch users. Normally, pressing down a Morse key for a short or
long time enters the dots or dashes. However, if the user can
manage two switches, then the dots can be entered with one switch
and the dashes with another.
The drawback with Morse (or any other learned code) is that
there are so many functions needed that the codes become very
cumbersome and hard to learn.
In HandsOff, this is overcome by embedding the Morse code within
a normal scanning grid. The user’s Morse file can be edited
in Notepad, allowing additional codes to be added for basic
punctuation, selection of prediction and so on. However, these
additional codes are kept to a minimum. When the user wishes to
select a rarely used character or a special command function, he
enters a special Morse code that drops back to auditory
A fairly large proportion of the users of these systems also have
a speech problem.
The talking word processor can be used for real time
conversation, but stored phrases make life much easier. HandsOff
allows grids to be used as message banks, with phrases stored in
the cells. To make this useable, the spoken prompt is a shortened
version of the message.
The prompts may be kept private if necessary, as the prompts are
spoken on the right hand channel of the sound system only. Thus
an earphone may be connected to this channel and a speaker to the
The people who have been using this combination of software and
techniques are progressing rapidly. One has graduated from total
passivity in the residential facility where she lives to active
participation and writing articles for the newsletter. The
elements that have given success are:
Ensuring that the programs really work in harmony, requiring
some specific software fixes. Re-thinking the way that the grid
design interacts with the target application. Patient support
from a trainer/helper who is regularly available. A great benefit
of the system is the possibility for future expansion. Not only
can new grids be made for other speech-enabled software, but
HandsOff can also plug many of the gaps in the speech output of
other talking programs. You don’t need to have a talking
menu in your application if you can make your own virtual menu in
a HandsOff grid.
Another advantage is that users can practice with the system
without the trainer being present all the time. With training
time being so precious, this is important.
There is no doubt that people with profound multiple handicaps
have frequently depended on systems that are complex to learn,
and limited in functionality. The effort to get the software
right, and to develop effective ways to use it, is already paying
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