Access do PC

Access to PC

Increasing the IMPACT of assistive technology - Communication impairments module, version summer 1999

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Cerebral palsy is defined as an impairment of the co-ordination of muscle action with an inability to maintain postures and balance and to perform normal movements and skills. These motor problems are of several types, depending on the location of the brain lesion. Over 80% of people with cerebral palsy have varying types of

difficulties in producing speech and some of them are severely speech disabled. The speech problems are associated with poor respiratory control due to muscular weakness and other factors, laryngeal and velolaryngeal dysfunction and oral articulation disorders that result from restricted movement in oral-facial muscles.

Some people with cerebral palsy also have language-cognitive communication impairments. There are about 6,500 people with cerebral palsy (0.13% of the population) in Finland and in the United Kingdom, Scope (a main organisation for people with cerebral palsy), estimates that 1 in 400 live births (0.25% of live births) has cerebral palsy.

Communication impairments are more complicated to solve than vision, hearing or physical impairments. Assistive technology

solutions are thus often more time-consuming to produce than those examined in other modules. The most important thing to remember is to be willing to communicate and to allow the person time to communicate. Aided communication should always be regarded as a coherent linguistic entity of an individual. The codes used by speech-motor impaired people, such as those with laryngectomies or amyotrophic lateral sclerosis, may consist of combinations of graphics, gestures, vocalisations etc.

The codes used by language-cognitive impaired people, such as those with learning difficulties or aphasia, are even more complex,

due to the difficulty of using any language to be translated directly from one linguistic code to another.

In both cases, the messages expressed through communication aids are often only fully transmitted when completed by body language and context which need to be individually known. It is therefore impossible to educate professional augmentative and alternative communication (AAC) interpreters at group level, nor is it possible to make software programs for exact translation.

There are various forms of ACC which take the place of spoken language including devices such as communication charts, electronic

communication devices and software programs. We have divided them into three categories: low-tech and high-tech, according to the technology used, and technical devices, comprising equipment by which one can produce and amplify sounds and voice.

Low-tech devices Low-tech devices are non-electronic systems or devices such as picture communication boards and charts or paper and pencil or they can be simple electronic communicators. Low-tech does not mean that they are inferior to high-tech devices – they offer the user a quick, powerful and flexible method of communication.

Simple communicators like this one can be used with children in training them to use communication devices.

Communicators have a symbol and a recorded message, which the user activates by pressing the symbol.

Because there are no electronic parts and no batteries, communication boards don’t give the option of speech output. The communicator must indicate to their communication partner which symbol, letter or word is being selected. The communication partner must in turn watch and then read, translate or interpret the message. Low-tech communication systems require both the user and communication partner to be actively involved in the interaction (Scott, 1998).

Pointing to, or touching, the required symbol on a display is a common method of accessing a low-tech communication system.

This may be achieved with direct selection, most commonly by finger or fist pointing, although elbows, toes and feet can also be

used. A technique of ‘eye pointing’ can also be used, where the person directs their eye gaze at the desired object or symbol on the

display (Scott, 1998). Speech impaired people can also instruct with gestures, mimes or text, used in combination with symbols and

pictures (Thursfield, 1995). It is also possible to use scanning techniques (‘listener scanning’) to access a low-tech communication system. The communication partner indicates, one by one, or group by group, the items presented on the communication display, and the AAC user indicates the desired group by eye blinking, for instance, or by vocalising.

High-tech devices

High-tech devices are simple or sophisticated electronic devices including simple communicators, dedicated communication systems

and computer systems programmed to provide communication capabilities. Computer systems consist of a special purpose computer

and software with symbol library, and digitised sound or a speech synthesiser can be used for output. In simple devices a combination

of symbols can also represent a message, and digitised sound or a speech synthesiser can be used for output.

Dedicated communication aids are designed solely for the means of providing an alternative to oral speech or to augment an individual’s speech. In some devices a visual or printed output of messages is possible. The system chosen for use may be known as the selection set. The most commonly used selection sets are either symbol/icon based or text-based. The latter systems usually use a standard form of alphabetic letters and numbers and are suitable for people who can read and write. The display of these letters may be the QWERTY layout, an alphabetical layout or a special display based on the statistical frequency of occurrence of letters in the language. Lightwriter displays letters with the QWERTY layout. It has two screens - one for the user and the other for the partner

Symbol/icon-based systems use different pictorial or graphic symbol sets or systems. For those who use symbols and pictures for

communication there are a variety of electronic communication devices with voice output. Small models with fewer symbols are

easier to carry along. Messagemate with symbol keys, which, when pressed, produce the

recorded message. Bigger models usually have space for bigger symbol selection sets. The user needs to memorise more combinations of symbols to retrieve a specific vocabulary.

Myweb Myway

www.bbc.co.uk/accessibility/archive/factsheets/pdf/ld_computing.pdf

Choosing the right input and output devicesis as important as choosing the right software to use. There are a range of adaptations and alternative devices that may be of use for people who find the standard keyboard and mouse difficult.

Pointing Devices

Some people with learning difficulties find it hard to relate the movement of their hand on the mouse to the movement of the cursor on the screen. In these instances, it may be that a trackball or a joystickis easier to use. A more direct approach is a touch screen. Some people may find it easier to point to things and this can be applied to using the computer. Touch screens act in

the same way as a standard screen but have sensitive surfaces. It is also possible to put a “Touch Window”over the front of a standard monitor to give the same function.

Keyboard

A standard keyboard has over 100 keys and to some users this can appear confusing, intimidating or can be an invitation to fiddle. The keys are fairly small and close together, usually in black and white/beige, uppercase and in a QWERTY layout.

There are many alternatives to the standard keyboard, some ideas are:

· Keytop stickers– these are available in a variety of colours and in upper/lowercase to stick onto the keys.

· Simplified keyboards – especially the ‘Big Keys Plus’. The keyboard is simplified with just the keys necessary for writing. The keys are large with an audible

click. Available in alphabetic / QWERTY and black and white / multi-coloured.

· Lowercase keyboards – as a standard keyboard but with lowercase letters.

· Overlay keyboards – These are touch sensitive membranes with keyboard overlays which slide over the top and determine the functions of the keyboard.

Overlays can be customised to have larger keys, less clutter, bigger gaps between keys and exclude unnecessary keys. This meansthey can be set up to whatever the user needs. In addition to just letters, overlay keyboards can also work with whole words or pictures. This is why they can be particularly good for people with learning difficulties.

Switches

If the user is physically or cognitively unable to use any keyboard or pointing device, then a basic starting point may be to use switch input. A switch is simply a button which, when activated, sends a signal to the computer. This signal can then be used to drive various software packages.

Switches come in a variety of shapes and sizes and can be operated by any controlled movement of the body.

Switches work well with cause and effect software and programs that require simple choices. A small switch interface box is needed to connect a switch to a

computer.

Output

Effective output from the computer is often key to effective use of computers by people with learning difficulties. Bright, colourful and active screenscan be helpful

– though take care not to make them too cluttered. Larger text and large monitorshelp and it is often suggested that to intensify the image it may be good to work

in a darkened room.

The sound facilities on computers can be utilised to the full – speech, sounds and music are available from many applications. To heighten the ‘cause and effect’ experience, the sounds should be in response to the user’s actions. Also, if the speakers are as close to the monitor as possible it will help concentrate the user’s attention to one area and reduce possible distraction.

Software

Once access to the computer has been established, the next step is to choose appropriate software to run on the computer. Software is available for a whole range of needs – these include very simple programsfor stimulation, to encourage vocalisation and switch and mouse programs which introduce ‘cause and effect’. More advanced programsare available for numeracy and literacy, memory and cognition.

The software needs to be stimulating and motivating and able to grab and hold the user’s attention. Colours, pictures, animation, large text, sounds and speechcan all help. The software should also have appropriate and attractive rewards for good work and not be discouraging when the wrong answer is given.

It is recommended that software is chosen by people working with the individual such as family, carers and teachers. A good approach is to have a look through the catalogues of the suppliers of the specialist technology, these tend to be very colourful and give comprehensive clear descriptions of the software.

Addapted from :

European agency for development in special needs education

BBC - Myweb Myway: http://www.bbc.co.uk/accessibility/archive/factsheets/pdf/ld_computing.pdf

1.Be able to move the pointer anywhere on the screen with an accuracy of a few  millimeters

2.Be able to click (validate) and double-click without moving the pointer

3.Be able to click and simultaneously move the pointer.