Children with autism spectrum disorder experience a wide range of communication differences, from minimal speech to extensive vocabulary with challenges in social use of language. Augmentative and Alternative Communication (AAC) provides powerful tools to support communication—and research consistently shows it supports, not hinders, speech development. One-third to one-half of minimally verbal children with ASD benefit significantly from AAC intervention.
Communication differences in autism spectrum disorder (ASD) vary enormously from person to person—this is why it's called a spectrum. Some children are minimally verbal or nonverbal, while others have extensive vocabularies but struggle with the social use of language (pragmatics). Some children use echolalia (repeating words or phrases they've heard), which actually serves important communication functions.
It's essential to understand that challenges with spoken language don't mean a child has nothing to communicate. All behavior is communication. Children with autism who don't speak may be communicating through actions, gestures, sounds, or behaviors that adults can learn to recognize and respond to.
Research shows that approximately 25-30% of children with autism remain minimally verbal (fewer than 30 words or no functional speech) despite intervention. However, this doesn't mean they can't communicate—it means they need alternative ways to express themselves.
Augmentative and Alternative Communication (AAC) is an umbrella term for all forms of communication other than oral speech. 'Augmentative' means adding to speech, while 'alternative' means instead of speech. Most AAC users fall somewhere in between—using AAC to support or supplement their verbal communication.
The National Clearinghouse on Autism Evidence and Practice recognizes AAC as an evidence-based practice for autism. Research shows that AAC is particularly effective when combined with naturalistic developmental behavioral interventions (NDBIs), producing larger effect sizes than NDBIs alone.
One of the most important findings in AAC research is that AAC does NOT prevent or delay speech development—and may actually facilitate it. This addresses a common concern among families who worry that using AAC will reduce motivation to speak.
Multiple studies show that children using AAC often increase their verbal output. A 2024 meta-analysis found that combining AAC with naturalistic developmental behavioral interventions produced 'notably larger' effect sizes for language outcomes than interventions without AAC.
High-tech AAC (speech-generating devices) has shown particularly strong effects on social communication, interaction, and speech production. Importantly, children also generally prefer high-tech options—in comparative studies, 35 of 44 participants preferred SGDs compared to 7 who preferred PECS.
PECS was developed in 1985 by Andy Bondy, PhD, and Lori Frost, MS, CCC-SLP, and is now one of the most widely used and researched AAC systems for autism. The protocol is based on applied behavior analysis (ABA) and B.F. Skinner's principles of verbal behavior. Over 240 peer-reviewed studies support its effectiveness.
PECS teaches functional communication through a structured, systematic approach that progresses through six phases. Critically, PECS doesn't require eye contact, imitation, or prerequisite skills—children can begin immediately. Research shows effect sizes of 0.91-0.97 for improving requesting, vocalizing, and motor imitation.
High-tech AAC options have grown enormously with tablet technology. Speech-generating devices (SGDs) produce spoken output when a user selects symbols, pictures, or types text. Research shows SGDs have effect sizes of 0.68-1.0 for improving requests and communication skills, and children generally prefer them over low-tech options.
Modern AAC apps offer different vocabulary organization systems. Understanding these systems helps families and therapists choose appropriate tools for individual children.
Visual supports leverage the visual processing strengths common in autism. They provide permanent, consistent information that reduces reliance on auditory processing and memory. Visual supports are not just for non-speaking children—many verbal children with autism benefit enormously from visual structure.
Parents and caregivers are the most important communication partners for children with autism. The strategies you use at home have enormous impact on your child's communication development. Research shows that parent-mediated interventions—where therapists teach parents strategies to use at home—produce strong outcomes for communication.
Children with autism have the right to appropriate education support, including communication support across the school day—not just during speech therapy sessions. An Individualized Education Program (IEP) should address communication goals that are meaningful for the child's participation in education and social activities.
Research consistently shows that early intervention produces better outcomes for children with autism. The brain is most plastic in early childhood, and children who receive appropriate support early often make significant gains in communication.
If you have concerns about your child's communication, don't wait. Early intervention services in BC are available for children under 6, and speech-language pathology services can begin in infancy.
Research conclusively shows that AAC does not prevent speech development. In fact, many children increase verbal output after beginning AAC. Don't wait—introduce AAC early if your child needs it.
The single most important strategy for AAC users: communication partners should model using AAC throughout the day. Children learn AAC by seeing it used, just like they learn speech by hearing it.
Always assume your child has something to communicate and the capacity to learn. Children often understand far more than they can express. Provide rich language input and robust AAC vocabulary.
When a child can't communicate through words or AAC, they communicate through behavior. Challenging behavior often indicates an unmet need or an inability to communicate something important.
Pragmatics refers to the social rules of communication—knowing what to say, how to say it, when to say it, and to whom. Social communication skills are essential for making friends, succeeding in school, and navigating daily life. Children with social communication difficulties may struggle with conversations, making friends, understanding unwritten social rules, and interpreting nonverbal cues.
Learn moreSpeech therapy apps can supplement professional therapy and make home practice engaging. However, apps should complement—not replace—working with a speech-language pathologist. The best apps are those recommended by your therapist to match your child's specific goals. Here are some SLP-recommended apps across different goal areas.
Learn moreChildren with Down syndrome often have language and communication differences that benefit from early, ongoing support. Speech and language development is influenced by multiple factors including muscle control, health, hearing, vision, and communication experiences. Visual learning strategies and integration of communication into daily activities are particularly effective, and most children make excellent progress with appropriate intervention.
Learn moreBritish Columbia offers several publicly-funded programs supporting children's speech and language development. Understanding what's available—and how to access it—helps families get the support their children need. This page covers provincial funding programs, regional health authority services, and local organizations in BC.
Learn moreOur team is here to help. Book a free consultation to discuss your concerns and learn how we can support you or your child.
Social Communication and Pragmatic Language Intervention
Many children with autism—including those with strong verbal skills—struggle with the social use of language (pragmatics). Pragmatic language skills include initiating conversations, taking turns, staying on topic, understanding jokes and sarcasm, reading social cues, and adjusting communication style for different people and situations.
Research shows pragmatic language difficulties are significantly associated with emotional difficulties and peer relationship problems. Evidence-based interventions can help children develop these skills.
Evidence-Based Approaches
Strategies for Home