Page 200 - Handbook of Electronic Assistive Technology

188 HANDBOOK OF ELECTRONIC ASSISTIVE TECHNOLOGY

AAC

Recep ve / Expressive

High-Tech
Unaided Low-Tech

• Formalised sign • Communica on Books Commercially Available • Modified Mainstream • Bespoke
Specialist apps on
•
Dicta on soware
Systems
languages • Communica on Boards • Text-to-speech mainstream built as
• Suppor ve tablets dedicated
signing systems • Rugged cases AAC
(Makaton and devices
Signed English)
• Natural gesture Representa on Method / Selec on Set
• Facial expression
Le ers / Words Phrases Symbols / Photos
FIGURE 7-2 Classifications of augmentative and alternative communication systems�
specialist apps and both bespoke and commercially available software. For an indepen-
dent and comprehensive database of low-tech and high-tech AAC devices and software,
the reader is directed to the Speech Bubble website. 3
It is worth noting that the terms high- and low-tech refer to the level of technologi-
cal complexity and not necessarily the complexity of the language that each system can
generate. It is also important to remember that most people who use AAC are likely to use
multiple systems dependent on communicative function, conversation partners and con-
text, often including unaided, low- and high-tech methods.
The representation method used in an AAC system is also part of its classification, and
refers to the way in which language concepts are represented for the user. As discussed
previously, these might include written letters or words, graphic symbols or photographs.
In the field of AAC, the array of items from which a user chooses to construct and generate
messages is referred to as a selection set.
It has been proposed that high-tech AAC systems can be further categorised into those
which are commercially available, such as dictation or speech-to-text software, systems
based on modified mainstream technologies, such as apps installed on tablet computers,
and custom or bespoke systems built specifically for voice output (Cook et al., 2014). For
example, an AAC user with good fine motor and cognitive skills may be able to make use
of a commercially available tablet with a built-in voice synthesiser to support the genera-
tion of written words and phrases. However, where additional impairments of motor or
cognitive functions exist, technology may need to be modified to meet the user’s needs.
Similarly, where physical movement is severely impaired or absent, for example, in clients
with motor neuron disease, the use of highly specialist systems such as eye-gaze control
technology or switches may be necessary to facilitate the selection of desired items on a
communication aid.

3 http://www.speechbubble.org.uk/.