There is a wide range of devices available for people who have communication difficulties. These range from simple devices with a single or only a few messages, to complex devices or portable computers.
Electronic Aids may be used along side, or instead of, other systems, such as paper based charts, signing systems, and other low tech methods of communication.
Few people with communication difficulties will use only one particular method of communication. In most cases somebody using an electronic aid will reinforce its messages with gesture, head movement etc.
Complex aids which can hold up to 32 messages, such as the Tech/Speak 32, are fairly simple to use, given that the user has an appropriate access method. These machines usually have a fixed vocabulary with a single key providing the same single message each time it is pressed. Some devices extend this by using levels. Levels enable the user to switch 'speech sets', that is the words or phrases stored in each key for another preprogrammed set. For example a user may a level for home, another for school and another for shopping.
The more complex aids, such as the Liberator (from Liberator) and the Dynavox, have the ability to hold a large number of messages. The user is usually able to combine key presses or selections to produce different messages. In this way, a machine with a limited number of keys is able to produce a much larger number of messages.
Different messages are usually selected by the user pressing a combination of keys, or by using a dynamic screen display which changes so that the user is presented with different arrays of messages.
Many users of electronic aids use a symbol or pictorial system to associate the images with larger messages. For those users who are able to spell, more complex machines allow them to type in messages which the machine then turns into speech using speech synthesis, as in the Lightwriters (QED).
Increasingly, portable computers are being used as electronic communication aids by running specialist software. This operates in much the same way as the purpose-built communication aids. Computers can provide the user with access to a wider range of options, for example, a child in school can use the computer both as a communication aid and as a method of accessing the curriculum. However, for some users the computer is too limited, for example, portable computers have limited battery life, unless connected to special external battery systems: whereas an electronic communication aid is designed to run for a whole day on one charge of its batteries.
Choosing an Aid
The different electronic communication aids have a wide range of facilities and capabilities. Choice of a particular aid for an individual will require careful assessment of the abilities and needs of the individual so the best device can be chosen.
The majority of aids arrive empty and need to be programmed with suitable messages and a structure to suit the individual. Some machines have pre-planned frameworks of messages which can be further tailored to suit the individual. However, it must be understood that even doing this can be a rather complex task.
Nobody should embark on trying to introduce an electronic communication aid to someone without giving full consideration to the amount of support and help that will be necessary to ensure that the machine will be used effectively.