Choosing the Right AAC System: A Behaviour Analyst’s Perspective

Augmentative and Alternative Communication (AAC) covers everything from a simple gesture to a sophisticated speech-generating device. Selecting the best fit matters - not just for day-to-day communication, but for skill acquisition, generalization, and behaviour reduction. Below, we unpack the main AAC categories, weigh their pros and cons through a behaviour-analytic lens, and share practical tips for families served by The Nest Family Behaviour Support Services.

Quick-Glance Comparison

AAC Type	Typical Examples	Key Strengths	Main Limitations	Best-Fit Learners
Unaided AAC	Natural gestures, manual signs	Always available; zero cost; promotes prompt fading	Limited to partners who know the signs; fine-motor demand; no voice output	Learners with good motor imitation and consistent communication partners
Low-Tech Aided	PECS book, photo/picture boards	Portable; durable; supports error-less teaching; easy data collection on exchanges	Requires physical manipulation; vocabulary is fixed; less socially “age-appropriate” for older users	Early communicators or those building foundational manding skills
Mid-Tech Aided	Single/step recordable buttons, GoTalk 9+	Simple to programme; powerful for early requesting; low cost	Limited vocabulary; relies on communication partner for navigation	Learners working on cause-and-effect or single-word requesting
High-Tech Dedicated SGD	Tobii Dynavox I-Series, PRC Accent	Robust vocab; dynamic pages; eye-gaze or switch access; research shows speech gains alongside device use	High price; requires charging/maintenance; training burden for teams	Users needing large vocab, alternative access (eye gaze), or literacy growth
Consumer Tablet + AAC App	iPad with Proloquo or LAMP	Lower cost than dedicated SGDs; quick updates; familiar hardware	Easier to distract (games/apps); may lack funding coverage; breakable	Learners mainstreamed in tech-rich settings, families comfortable with tablets

1. Unaided AAC (Gestures & Manual Signing)

Pros

• Zero device dependency - gestures are always available, supporting generalization across settings.

• Low response effort for partners once they learn the sign repertoire, enabling faster reinforcement delivery.

• Prompt-fading friendly; signs can transition to vocal approximations if speech emerges.

Cons

• Listener barrier - communication breaks down when partners do not know the signs.

• Fine-motor demands may limit accessibility for learners with motor planning challenges.

• No permanent record of responses, making data collection harder.

2. Low-Tech Aided AAC (Picture Boards, PECS)

Pros

• Concrete symbols reduce abstraction, ideal for early mand training.

• Physical exchange creates a natural opportunity for differential reinforcement.

• Evidence-based - multiple studies show PECS supports requesting and may increase spontaneous speech.

Cons

• Manual handling (velcro strips, pages) can slow the rate of communication.

• Risk of loss or damage to "words"

• Stigma for older users who may feel boards look “childish.”

• Vocabulary limits - adding words means printing/laminating new icons.

Predictors of successful PECS use include strong reinforcer motivation and consistent communication partner training.

3. Mid-Tech Aided AAC (Single/Sequential Message Devices)

Pros

• Cause-and-effect is crystal-clear - great for early language learners or those with severe motor or cognitive delays.

• Quick to programme; no specialized software.

• Budget-friendly entry point while families pursue funding.

Cons

• Few messages restrict communicative functions (e.g., commenting, social closings).

• Physical durability vs. vocabulary trade-off - more buttons ≠ more robustness.

Behaviour analysts often use these devices in mand (request) trials before moving to systems with larger lexicons to maintain momentum and minimize frustration.

4. High-Tech Dedicated Speech-Generating Devices (SGDs)

Pros

• Dynamic displays & core vocabulary allow novel sentence construction - key for generative language.

• Access options (eye-gaze, head mouse, single switch scanning) ensure inclusivity.

• Funding streams (ADP in Ontario, private insurance) frequently cover these “medical” devices.

Cons

• Training intensity - teams need competence in programming, prompting hierarchies, and data collection.

• Technical issues (battery, software glitches) can interrupt sessions, requiring backups.

• Higher upfront cost than tablets.

  
  

5. Consumer Tablets Running AAC Apps

Modern AAC apps like Proloquo now ship with 16 000+ pre-stored words and guided modelling features, shrinking the learning curve for parents.

Pros

• Affordability and familiarity - families already comfortable with tablets tend to model more often, boosting stimulus control.

• Regular updates & custom voices keep content relevant and engaging.

• Portability + multipurpose (can also show schedules, video models).

Cons

• Distraction risk - availability of games/social media may compete with communication during sessions; behaviour analysts should set up Guided Access.

• Less rugged; cases and insurance are essential.

• Funding ambiguity; some provincial programmes, including OAP, still prefer dedicated SGDs.

  
  

Behaviour-Analytic Takeaways

1. Functional Match Over Device Hype: Conduct a full Functional Communication Assessment; align the AAC’s response effort with the MOs (motivating operations) identified.

2. Plan for Generalization: Train caregivers across multiple contexts; reinforce communicative attempts immediately to prevent extinction bursts or resurgence.

3. Data Drives Decisions: Whether it’s PECS Phase 2 success rates or SGD spontaneous utterance counts, consistent data collection tells us when to move up the AAC hierarchy.

4. Ensure Stimulus Control Transfer: Fade prompts systematically - from physical to gestural to natural cues - to avoid prompt dependency.

   
   

Final Thoughts

No one AAC system is universally “best.” Optimal outcomes flow from an evidence-based match between learner abilities, communicative goals, and environmental supports. Behaviour analysts at The Nest Family Behaviour Support Services tailor AAC recommendations through ongoing assessment, caregiver coaching, and data-guided adjustments.

Have questions or need an AAC consultation? Reach out to our team - we’re here to help every voice be heard.