Glossary of terminology used in AAC devices
AAC - Augmentative and Alternative communication. A mode of expressive communication, replacing or supporting actual oral speech; used to express ones’ needs, ideas and thoughts etc.
People with severe speech or language problems rely on AAC to complement existing speech or to replace lost non-functioning speech. Additional (augmentative aids), such as photos, pictures, visual-graphic symbols, communication boards and electronic devices, are all used to help people express themselves. This may reduce social exclusion and increase social interaction, personal independence and feelings of self-esteem.
What are the types of AAC systems available today ?
There are many types of AAC available. AAC systems generally fall into two categories: Aided. and Unaided
Aided communication devices provide some type of voice output either digitised (recorded real human voice files) or synthesised (machine generated speech output) These devices display topics, symbols, messages, letters, words, and phrases, to be spoken. Popular and well-known manufacturers of AAC devices are: Boardmaker, Chat PC, Dynavox, Lightwriter, Sensory Grid, Say it Sam, Tellus, TouchSpeak and TypeSpeak, Widgit, etc.,
Unaided communication systems do not provide any voice output and would include: Pictures, communication boards, gestures, drawing, body language, sign language etc.
Abbreviation Expansion is a keystroke-saving feature, offered by some communication software programs. This feature allows users to abbreviate a phrase, message or sentences. ‘eg’ expands to “for example” in full when the user enters these letters. With more sophisticated systems, such as TypeSpeak, an entire abbreviation structure can be created.
Dedicated Communication Device is an electronic communication system designed solely for the purpose of communication. This may be a dedicated discrete unit or just as likely to be a commercially available consumer device (such as PDA) but with restricted or limited access to the standard built-in applications, such as the Contacts, Appointments Diary etc.,
Digitized Speech is n
ormal
recorded human speech. Digitized speech has excellent intelligibility, but is less flexible than synthesized speech and is not immmediately available 'on demand'. Some users express a preference for a 'familiar voice'.
Eyegaze Systems allow full access to a computer via a mouse emulator which controlled through the user’s eye movement contained in a head set (see Head Controlled Mouse).
Frequency (of Word Prediction)
Head Controlled Mouse allow full operation of the computer via a mouse emulator controlled through the user’s head movement.
Recency (of Word Prediction)
Scanning and Switch Access are means and methods of selecting items displayed in a communication system. The items are presented to the user in a fixed sequence. The user waits until the desired item is presented and then chooses it. This selection technique are used with both electronic and manual communication systems.
SNUG (also known more prosaically) as Spontaneous Novel Utterance Generator. This enables to the user to participate in a conversation - either to initiate or to reply.
Symbol System is a organised system of symbols used to identify a topic to display or speak its associated message. The contents can be anything which can be represented and understood in pictorial form (pictures, photos, pictograms etc. The most widely-known and commonly-used formalised and structured system in use today, is that of the Mayer Johnson PCS image library, also known as Pictorial Exchange Communication System.
Synthesized Speech is artificial speech that has been created by electronically combining sounds to produce words. Intelligibility ranges from poor to excellent. Although it has a more artificial sound than digitized speech, it is more flexible, as messages need not be prepared in advance. Some users prefer the consistency of the non-inflected spoken output, particularly when used in an unfamiliar social environment
Word Completion & Word Prediction is a keystroke-saving option offered by some communication devices and programs. This allows the system to "best guess" what the user is typing. As letters are typed, the user is offered a list of words predicated on the letters already entered - the word prediction. If the desired word is on the list, the user selects it and the computer types the remaining letters automatically – the word completion. The list is often refined by Frequency and Recency rules.
