Augmentative Alternative Communication (AAC)
Synthetic Speechchild using speech generating device
There are many types of uses of synthetic speech today. Besides giving voice to non-verbal persons, screen-readers help those with low vision and blindness navigate documents and web pages. Today's global positioning systems verbally point drivers in the right direction, and synthetic speech prompts automated phone systems and equipment.
For over a generation, synthetic speech devices (known as augmentative alternative communication or AAC devices) have been utilized for verbal communication by persons with speech-language disorders. AAC devices connect people of all ages to people at school, work, and recreation. Today other terms may be used for these devices such as speech generating device (SGD) or a voice output communication aid (VOCA).
Who Uses Augmentative Alternative Communication (AAC)?
AAC users are children and adults with communication disorders due to cerebral palsy, autism, Down syndrome, ALS or Lou Gehrig's disease, stroke, traumatic brain injury, multiple sclerosis, and Parkinson's disease.
What does an AAC device do?
Many people who use AAC systems have a combination of high tech and low tech.  After all, no one communicates in the same way all the time.  We shrug our shoulders.  We wrinkle our noses.  We shake our heads.  We grunt agreement.  Before computers were invented, a simple picture board was made with pictures to describe typical wants and needs. A non-verbal person could point to a picture of a hamburger to say "I'm hungry," or a book to say "I'm going to do my homework now." These types of communication boards or books continue to be used today.  At times, they are preferred over high tech due to environmental considerations.  After all, computer based systems don't work so well in swimming pools! Some are used as backups when computerized systems fail or need repair.  Others are the method of choice.
Now we also have sophisticated electronic communication devices. Electronic AAC devices give users unlimited ways to express themselves. Users spell out words, or use abbreviations, photographs, virtual scenes and symbols for short-cuts. There are all sorts of programming tools for AAC communicators to program messages and have ready for future use. These devices even interface with computers or have computer commands and browsers built in.

Note: The celebrated physicist with Amyotrophic lateral sclerosis (ALS), Dr. Stephen Hawking, has used speech devices for years in his professional and personal life. As a highly accomplished scientist, Hawking has produced entire documentaries about the universe, utilizing synthetic speech to narrate.

Easy, helpful features such as word-prediction may provide efficient use of an AAC device, along with new software options. Features can be basic speech output to complex functions, including access to environmental controls and other electric units, depending on skills and preferences. Users can personalize their output with a choice of synthetic voices, both male and female, young or old or program devices with human digitized speech.
With the entry of portable devices such as Windows tables or Apple's iPads, came apps to support the area of AAC.  The list of apps is extensive, but the reader should beware that many developers do not have a language background and are simply programmers.  These apps tend to not meet the needs of the AAC user.  For an extensive look at available apps, see Jane Farrall's website.
Learning to use a speech generating device takes time.  The use of Partner-Augmented Input (PAI) is often recommended during the learning stages.  This is a method of communicating whereby the communication partner points to the symbols on the communication board, book or device while simultaneously talking. l This method is used to meodel many communication functions- commenting, requesting, responding. Research suggests that PAI increases production of multi-symbol messages and improves utterance length and complexity. 
Below is a partial list of producers of AAC devices. We provide them just to acquaint new-comers with the range of possibilities in speech devices. Visit each company's website to learn about products and features. Ultimately, a speech-language pathologist is needed to perform a complete assessment and determine which equipment is most useful. An occupational therapist may be invovled if there is the need to attach a communication device to a wheelchair. 
Dynavox Mayer-Johnson (A Tobii Technology Company)
Dynavox Technologies offers a diverse line of speech generating devices and software, along with training and workshops offered nationwide.  They also carry Boardmaker sofware used to create symbol-based materials for students with limited reading skills.
PRC makes several AAC devices and is the originator of Unity, a languge system that uses pictures combined in short sequences to produce words, phrases and sentences.  
Saltillo produces the Nova Chat line of speech generating devices.  They also carry WordPower software which is word-based vocabulary with core vocabulary, spelling options and word prediction.
AMDi focuses on the design, engineering and manufacturing of augmentative communicators and electronic devices for governmental, medical, commercial and private customers.
Carries simple communication aids, talking photo albums, software and apps for AAC users. 
Avatalker AAC
Avatalker AAC is a full-featured AAC solution designed for the iOS platform (iPad and iPad mini). It is designed so the user can access all the words on one screen. By selecting from graphic images and realistic looking scenes, users can build phrases and sentences pictographically. There is a 1500+ word vocabulary and symbol set. 
Resources and Publications
Serves as advocacy group for legislation, has special interest group (#12), provides continuing education credits and publishes evidence-based practices for many areas, but includes AAC. 
Dr. Caroline Musselwhite's website features tips of the month, new products, handouts from presentations and a fabulous review of communication apps.
This is a wonderful resource about disaster preparedness for persons who use AAC devices. It contains checklists, visual supports, and social stories and information for emergency personnel, consumers, and caregivers.
Speakbook is a low tech eye gaze system developed by an individual who has ALS. The website contains a brief video of how it works and a link to download the template to create your own Speakbook.
Note: Infinitec Inc. does not endorse or recommend the above-mentioned products and has no liability for the results of their use. Infinitec Inc. has received no consideration of any type for featuring this product on this Web site. The information offered herein is a summary; it is not comprehensive and should be carefully evaluated by consumers with the assistance of qualified professionals. The intention of Infinitec Inc. is to offer consumers a brief overview of various assistive technology devices and their applications.