AAC can support communication across very different abilities, but the way a child accesses a system may determine whether the technology actually opens meaningful participation. This review shows both how far the field has moved and how much evidence is still missing.

Children with motor and speech disabilities represent a heterogeneous group who can benefit substantially from augmentative and alternative communication, or AAC. AAC technologies have been shown to support spoken language and communication development across a wide range of cognitive, linguistic, motor, and sensory profiles when access methods and intervention strategies are matched to individual abilities.

The review examines the current state of research related to AAC access and intervention. Children with motor disabilities face unique challenges in ambulation, use of their hands, and indicating their needs and interests. A majority of children with cerebral palsy have communication disability, and twenty to thirty percent do not have intelligible speech.

Children with neurodevelopmental speech and motor impairments are at increased risk for social isolation and decreased participation in communication interactions. A majority of children with cerebral palsy could potentially benefit from assistive communication technologies in the form of augmentative and alternative communication.

AAC has a strong evidence base across a wide range of communication impairments, skills, and needs, and is transformative in the lives of many individuals including those with cerebral palsy. Alternative access is a significant part of decision making within AAC services, and experienced speech-language pathologists often approach it as a separate portion of the AAC assessment for children with motor impairments.

This separate attention is necessary because there are multiple decision points around an access setup, each creating varying degrees of cognitive and attentional demands that must be considered. When alternative access methods are first introduced, the child’s focus is primarily on how the selection is made and less on what the linguistic or communicative message is.

The trade-off between how and what continues until the child has experienced success over time and contexts. Balancing the demands associated with motor access to communication messages is key to allowing meaningful linguistic content to drive active participation in communicative interactions.

Scanning options have evolved in at least three areas. The first area includes increased organization related to scanning patterns. In addition to linear and row-column scanning patterns, communicators can make custom scan patterns to maximize time efficiency.

The second area of evolution is the types of feedback available to support the individual as they scan: items can be magnified, shaded, or otherwise visually enhanced instead of using only a border highlight. There is little research supporting these visual feedback methods, although one study found that preschoolers without disabilities learned scanning faster with magnification than with the traditional border highlight.

Selections can be confirmed visually, auditorily, or through haptic or vibration-based feedback, and more research is needed to guide clinicians in assessing and recommending these features. The third area is how selections are activated, including mechanical switches, sip-and-puff switches, proximity switches, and electromyography-based switch activations that may benefit children with minimal motor movement.

Individuals with motor and speech difficulties such as cerebral palsy or multiple disabilities who could benefit from AAC have received little research attention in AAC intervention research. A scoping review of literature from the last two decades concerning individuals aged zero to twenty-one discovered only twenty-seven studies with fifty-five participants, and only sixteen appeared to use alternative access.

Most intervention research focused on requesting and choice-making in controlled environments, with minimal inclusion of communication partners. Only two research studies had focused on teaching communication partners to support people who benefit from AAC.

More recent research has included participants with multiple disabilities and their partners, addressed early language and literacy skills, and used mobile training platforms and telepractice to teach parents, professionals, and peers about AAC. Parents are essential for early language development and continued use of AAC into the home and community, yet very little AAC intervention research had included parents of young children with multiple disabilities until recently.

Brittlebank and colleagues taught intervention techniques to six parents of children aged three to eight with motor and speech disabilities through synchronous telepractice during shared storybook reading. The parents completed a forty-five to ninety-minute live education session that included video modelling, practice, and feedback during role-play.

All parents successfully learned extended wait time, aided AAC modelling, and responding and expanding on the child’s communication in a naturalistic interaction. Improvements were observed in child turn-taking and unique vocabulary expression following parent training, while all six children were able to use direct access on an iPad to some extent; positioning the system and child remained challenging.

Individuals with concomitant motor and speech disabilities should be supported beyond the first words stage with access to needed vocabulary and a means to generate language using symbolic forms of communication. Literacy skills support independent generative communication for people who use or benefit from AAC, yet many individuals with cerebral palsy have lower literacy than peers without disability.

This disparity may be due to a lack of adaptation of literacy instruction that relies on speech production, particularly for people who use alternative access methods, and AAC devices do not necessarily support a phonics approach. Very few studies have focused solely on adapting literacy instruction for people with motor and speech disabilities who may benefit from alternative access, and most literacy interventions have targeted early literacy skills.

In one telepractice example, individualized literacy instruction with three young adults with cerebral palsy supported letter-sound correspondence, decoding, and encoding; all showed some improvement in literacy skills and reported positive experiences. Recent inclusion of children and young adults with multiple disabilities in AAC intervention research is encouraging, but individuals with motor disabilities are a heterogeneous population, making large-scale research studies challenging to implement.

Research must deliberately include individuals who may benefit from alternative access. Much of the work to date has focused on foundations for early language development, including turn-taking, choice-making, and increasing vocabulary.

The need remains to support continued language development beyond the single-words stage. Much research has focused on unaided, low-tech, or basic functions of high-tech AAC systems, so attention to improving system design is needed to best support language and communication outcomes.

The central message is that AAC access and intervention must be matched to individual abilities, extended beyond early requesting and first words, and studied with communication partners included. Progress is promising, but targeted research remains essential.