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The ABC’s of Vision and AAC

Equipment
Low & high tech options

In developing an AAC system for someone who has VI, it is crucial to find ways to help the person receive information and learn, as well as communicate with others. This section focuses on tactile, auditory and visual symbols and devices specifically designed to assist people with low vision and blindness.

Symbols

Some people with low vision who don't speak can use print (i.e., text and/or graphic symbols.) Many others, including those who are blind, must depend upon tactile and auditory symbols to develop and use language.

Table II summarizes symbol options for AAC users who are blind or visually impaired.

Tactile symbols

• Tangible. Textured symbols, real objects or parts of objects can be used with very young children and those who have severe cognitive and language impairments. "Symbols" that become relevant and meaningful provide individuals with access to language. Only then can they be used to make requests, comment and so on. Tactile symbols are most easily used one at a time, but can be placed on low tech displays, switches and AAC devices. Few users with severe motor impairments are be able to communicate independently using tactile symbols (tangible or Braille.)
  
  
• Braille: A tactile symbol system for reading and writing used by a small percentage of persons who are blind. Many countries have adapted Braille to suit their language and cultural patterns. Braille characters are formed using combinations of six embossed (raised) dots arranged in two vertical columns—three dots in each. Each character may represent a letter, a part or an entire word or concept. Symbols exist for music notations (Music Braille code), arithmetic and mathematical computations (Nemeth code) and scientific notions and computer commands (computer code.) Table III lists products that allow individuals access to Braille materials.
  
  

Auditory symbols

• Morse code: An international auditory (or tactile) code for reading and writing. It consists of dot and dashes which represent letters, words, phrases, and more. Some AAC devices translate Morse code to text and speech.
  
  
• Speech. Speech and other auditory stimuli play a very important and powerful role in learning. Speech output is also used to enable people to access written language and graphics. Examples are talking books, reading machines, computerized books and screen reading programs. Talking watches and other consumer technologies are readily available. For some AAC users, listener-assisted and machine generated auditory scanning may be the only means of accessing language.
  
  Speech output as a means of expression is sometimes overlooked for AAC users with VI because AAC devices do not easily accommodate tactile symbols or large graphic symbols. This is truly unfortunate. How are people with low vision or blindness who can not speak supposed to interact with children, get attention and function independently in the community or classroom without speech output? AAC devices are beginning to offer features that will accommodate visual deficits, such as auditory scanning, auditory fishing and color displays with good resolution. In addition, digitized speech devices are low cost. Finally, synthesized speech allows access to computers and may be the best way for many to develop written and "spoken" language skills.
  
  

Visual symbols

• Print: The size, quality, contrast, line thickness, color, arrangement and position of text and/or symbols can be altered using both low and high tech solutions. Low vision devices provide access to printed materials under specific conditions. Examples are filters, magnifiers, sunglasses, large phone dials, special light pens, telescopes and telemicroscopes. Screen enlargers, closed circuit TVs, and optical character readers enable people with low vision to "see" print.
  
  

Table III gives a few examples of currently available devices for persons with VI or blindness, including some braille products and low tech visual aids.²⁰ Screen readers translate text and some graphics on computer displays to speech. Closed circuit TVs and screen enlargers provide magnification to enlarge print/symbols and enhance figure-ground contrasts. Optical character recognizers translate printed material into an electronic format that can be stored and accessed via a computer monitor, printer, synthesizer or braille display. In selecting equipment consider accuracy, rate, comprehension, comfort and fatigue. Currently, many AAC devices do not interface easily with devices designed to assist people with VI so check carefully with manufacturers!

 

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