AAC:
“Augmentative and Alternative Communication (AAC) are the words used to describe extra ways of helping people who find it hard to communicate by speech or writing. AAC helps them to communicate more easily.” [ISAAC, 2008] There are two main types of AAC system: unaided and aided. Most people who use AAC use a combination of unaided and aided methods.

Aided Communication:
“This is how we describe methods of communication which involve additional equipment, such as a picture chart, a communication book, a computer or special communication aid. Aided methods of augmentative communication may be ‘low tech’ or ‘high tech’. Both low and high-tech systems can be used by people who are unable to spell or read, as well as by people who are highly literate.”¹

VOCA: A Voice Output Communication Aid (VOCA) is “any device whose primary function is to use electronically stored speech as a means of communication.” ⁴ VOCAs can range from simple single-message devices which use recorded speech, to complex computer-based systems which store many messages and use an artificial or computer-generated voice. They are often referred to as ‘Talkers’
Low-Tech: “Low-tech communication systems may take many forms and are anything you can use which does not need a battery to function. Low-tech communication systems include a pen and paper to write messages, alphabet charts, charts and books with picture symbols or photos, and tangible symbols.”²

High-Tech: “High-tech communication systems are devices requiring at least a battery to operate. High-tech communication systems range from simple high-tech (e.g. single message devices, pointer boards, toys or books which speak when touched) to very sophisticated systems (e.g. specialised computers and programs, electronic aids which speak and/or print).”³
Within this project devices have been categorised into ‘high tech’, ‘mid tech’ and ‘light tech’. Those with a dynamic screen and a synthesised voice were either ‘high tech (medium to large size)’ or ‘mid tech (small or handheld size)’ whilst those with a static screen and a recorded voice (subdivided into ‘9 or more squares’ or ‘1 to 8 squares’) were categorised as ‘light tech’.

Unaided Communication:
“This is how we describe methods of communication that do not involve a piece of additional equipment. Body language, gestures, pointing, eye pointing, facial expressions, vocalisations, British Sign Language, and Makaton are examples of unaided methods of augmentative communication.”⁵

1,2,3,5: Communication Matters website

4: ACE Centre website