Assistive technology (AT) includes a range of tools, such as communication boards, voice output communication devices, computers, switches, and powered wheelchairs. Based upon the complexity of a student’s disability, they can benefit from multiple AT tools to enhance their classroom participation.

An augmentative communication (AAC) device may be a component of a student’s AT solution. An AT or AAC evaluation is indicated to determine the most appropriate technology solution(s) for a student. This article will focus on the process of selecting the most appropriate AAC device.

Students with a range of disabilities may benefit from an AAC evaluation. Some students will be ambulatory and have functional use of their upper extremities for pointing to a device or keyboard. Others may require use of alternative access tools ranging from switches, to joysticks, to eye-gaze devices. Some students’ speech impairment may be so severe that they require an AAC system – voice output device; PECS, picture boards; signs – to communicate with both familiar and unfamiliar listeners; others may only need an AAC system as a back-up to their speech when communicating with an unfamiliar listener or perhaps with a familiar listener outside of a known context.

Regardless of a student’s diagnosis and/or severity of their speech disorder, an AAC evaluation assessing the student’s abilities and evaluating multiple device options is indicated as the means of selecting the most appropriate AAC device. An evaluation also may provide AAC goals and strategies to support the student if a device is not indicated for any reason.

Pathway to Pathologists

An SLP knowledgeable in AAC should be the key person guiding the AAC device selection process. National associations such as the American Speech-Language-Hearing Association (www.asha.org), and state associations such as the New Jersey Speech and Hearing Association (www.njsha.org), provide professionals working in the field with training opportunities and other resources to build their competencies to provide AAC evaluations and treatment.

The SLP is faced with the difficult challenge of keeping abreast of the current AAC devices along with knowing the vocabulary organization strategies and features of each device. AAC device manufacturers often provide device demonstrations and training to AAC teams, and it is imperative that this be done outside the scope of the evaluation procedure to ensure an objective assessment.

In seeking a sole vendor’s support for evaluation and/or report preparation, SLPs may innocently put themselves in jeopardy of an ethical violation.

The AAC evaluation must include an assessment of the student’s:

• present communication status
• physical abilities and limitations
• visual and perceptual abilities and limitations
• cognitive/language abilities and limitations
• symbolic abilities and limitations
• behavioral considerations

An understanding of the student’s strengths and weaknesses in these areas helps to focus the SLP when considering the possible device options that would enable the student to meet targeted communication goals upon acquisition.

As a part of the AAC evaluation, the SLP identifies the communicative contexts for which the student needs an AAC device and defines the communication requirements associated within each context. While an AAC device may enable a student to participate more fully in their educational program, an AAC device need not be the primary or only tool that a student uses to master educational competencies. For some students, mastering educational competencies may be best met by having access to a computer complemented with educational or language learning software.

When assessing the student’s symbolic performance, the SLP identifies the size and type of symbols the student understands so that the student can use these symbols with communicative intent to satisfy needs, wants, and express, and to achieve relevant goals defined in the individualized education program.

Younger children and those with significant cognitive involvement often find it easier to identify symbols that are large, concrete, and realistic. As children mature, symbol size can be decreased and the symbol can become more abstract without comprising recognition or identification performance. It is important for the SLP to determine the size and type of symbols the student can use functionally, reliably, and with communicative intent.

Symbol size also may influence whether an electronic device is an appropriate system option. Electronic devices with touch screens – Saltillo Alt-Chat™, DynaVox V, PRC Springboard™ – present constraints in terms of the size of symbols that can be displayed and the number of symbols that can be presented at any given time.

Likewise, static display devices such as AMDi’s TECHSpeak or Smart 128 restrict symbol size to a predefined grid with a range of eight to 128 locations. The SLP must ultimately provide the student access to a device that provides the appropriate symbol size.

Manual (e.g., paper) communication boards or tangible symbol systems (www.designtolearn.com), can be designed to match the student’s specific needs and abilities. Each display format will obviously hold a given number of symbols, but the limitations imposed are more closely related to the abilities and needs of the student.

Many children who use AAC fail to generate complex messages despite their ability to understand them. Their aided messages often consist of a single symbol or perhaps use of a rote sentence pattern. Part of the evaluation process is to assess a student’s potential and ability to sequence symbols to formulate messages. The SLP should determine the student’s expressive language abilities and ensure that the selected system enables the student to develop linguistically to the fullest of their potential.

Throughout this article, the term “most appropriate” has been used repeatedly – this does not necessarily imply most expensive. For students with complex communication needs who also demonstrate significant motor limitations, the most appropriate device will likely need to not only accommodate communication needs and goals, but also have built-in features that address the student’s gross and fine motor limitations and enable computer access. As such, when a student requires a device with many features the cost of the AAC device may be high.

For students who have some speech, are ambulatory, and have good hand function, the appropriate AAC device may be a simpler AAC tool. In this instance, literacy, language learning, and educational needs can be addressed by providing the student access to a standard computer with educationally-relevant software rather than through the AAC device. Thus, the cost of the AAC device may be significantly less than for the complex device as described above.

The following two case summaries provide examples of appropriate AAC and AT outcomes for students who present with very different communication abilities and needs.

Case No. 1

G.M., an 8-year-old male, has a medical diagnosis of autism and a speech diagnosis of apraxia. He is ambulatory and has functional use of his upper extremities. He uses speech as his primary mode of communication. His intelligibility is estimated to be 80 percent for familiar listeners, who the majority of his educational team. He will also lead people to what he wants, use picture boards, and limited spelling.

G.M. demonstrates both a receptive and expressive language disorder. His spoken length of utterance is estimated to be 2.5 words. His speech is marked by use of nouns, verbs, adjectives, some prepositions (e.g., in, on), and intermittent use of the morphological marker “-ing”.

Test results from the Test of Aided-Communication Symbol Performance (TASP)  demonstrate that his spoken messages are consistently longer than the messages he can form when using an AAC device. They also indicate that his categorization skills are very limited for visual tasks and significantly impaired for auditory tasks, such that a basal could not be achieved.

Based upon the findings of his AAC evaluation, the evaluating SLP determined the Chat PC (Saltillo), a palmtop dynamic display device, to be most appropriate AAC device to serve as a back-up to G.M’s speech. The Chat PC is small enough for him to easily carry and hold while using it. It comes with symbol-based software that can be customized to G.M.’s vocabulary needs.

It was determined that the most appropriate AT solution for facilitating gains in his expressive language and spelling skills is to provide him access to a computer with educational software. Programs to build expressive language and syntax and to improve spelling skills were recommended. Since G.M. is ambulatory and does not have fine-motor limitations, language and spelling intervention need not be accomplished through use of the selected AAC device.

Case No. 2

K.F., an 18-year-old male, has a speech diagnosis of dysarthria and medical diagnosis of cerebral palsy. He has no functional speech. He is non-ambulatory, with functional use of upper extremities for driving his powered chair and for gross pointing. There are no hearing or visual limitations. K.F. is bright and has intact receptive and expressive language abilities.

In the past, he had a DynaMyte communication device. However, it was broken and could not be repaired. He was using a manual board as an interim tool, but it does not meet his communication needs within a university living situation.

K.F. needed an AAC device for use across all communication environments that offers him access to the alphabet, word prediction, a core word vocabulary, and pre-stored messages for quick communication. To meet his life goals of independent living and completing college, he needed an AAC device with high-quality voice output where he can create and store large bodies of text to deliver speeches and access a computer.

Since acquisition of his last device, K.F. is now able to use his thumb to access a touch screen. This mode of access was achieved with a keyguard and with the device positioned approximately 1 inch above his abductor wedge, a non-standard location for mounting SGDs.

It was felt that the DynaVox V with the adult Gateway 40 page-set was the most appropriate device. K.F. would require a keyguard and a custom mount to effectively and independently use the device across environments.

The role of SLPs in an AAC evaluation is ultimately to provide a student with a communication system that enables the development and/or use of language at a level commensurate with a student’s cognitive-language abilities. The AAC evaluation should lead to selection of the most appropriate AAC system. That is, the selected device should be the end result of a comprehensive evaluation that considered multiple device options selected on the basis of the student’s abilities, communication needs, and goals.


 — Joan Bruno, PhD, CCC-SLP, is the AAC specialist with Shrewsbury, N.J.-based TECHConnection and has more than 25 years of experience working in the AAC field. She currently serves as the vice president of the New Jersey Speech and Hearing Association. Direct questions and comments to editorial@therapytimes.com.