Chapter 3: Mid-Tech and High-Tech AAC
Core Foundations and Bibliographic Context
Publication Title: Fundamentals of AAC: A Case-Based Approach to Enhancing AAC
Authors/Editors: Nerissa Hall, Jenifer Juengling-Sudkamp, Michelle L. Gutmann, and Ellen R. Cohn
Chapter Title: Chapter 3: Mid-Tech and High-Tech AAC
Chapter Author: Elena Fader
Copyright: © 2023 by Plural Publishing, Inc. All rights reserved.
Learning Objectives
Feature Comparison: Compare key structural, functional, and technological features of mid-tech and high-tech augmentative and alternative communication (AAC) devices.
Systematic Evaluation: Establish a systematic, evidence-based procedure for evaluating and considering technology-based AAC systems for clinical candidates.
Clinical Generalization: Generalize clinical applications of tech-based AAC to serve a broad range of individuals with diverse linguistic, physical, sensory, and cognitive profiles.
Community Integration: Integrate the individual's family, social network, and broader community into every stage of the AAC implementation process.
Terminology and Key Concepts
Mid-Tech AAC: A battery-operated AAC device that utilizes digitized, or pre-recorded, voice messages for speech output.
High-Tech AAC: A tablet- or computer-based AAC device that utilizes synthesized speech generated via computational algorithms and linguistic coding to convey messages.
Voice Output: The primary auditory acoustic feature of mid-tech and high-tech devices that distinguishes them from lite-tech (paper-based) AAC tools.
Digitized Speech: Recorded human voice speech used for the purpose of AAC auditory output.
Synthesized Speech: Artificially produced human-sounding speech generated from text inputs using specific algorithms and linguistic rules.
Language System: The software program or application interface that presents vocabulary, grammar structures, and communicative organization to an AAC user.
Spontaneous Novel Utterance Generation (SNUG): The ultimate linguistic goal of AAC intervention, defined as the ability of an individual to express any message, on any topic, at any time.
Device Abandonment: The failure to use an AAC device to its full capacity, or the total discontinuation of device use, occurring primarily when adequate operational and clinical training is not provided to the user and their communication partners.
General Principles of Mid-Tech and High-Tech AAC
Aided AAC Domain: Both mid-tech and high-tech systems are classified as aided AAC because they require external physical equipment, tools, or technology beyond the user's body.
Functional Goal: Designed to supplement (augment) or fully replace (alternative) existing verbal speech capabilities.
Target Population: Provides broad clinical utility for individuals of all age groups presenting with diverse linguistic, cognitive, sensory, and motor needs.
Mid-Tech AAC Hardware and Operational Specifications
General System Characteristics:
Mechanical push-buttons or pressure-sensitive keys.
Battery-powered operation.
Digitized voice output capable of storing single or multiple recorded messages.
Access capabilities include direct selection (touching display/buttons) and indirect selection (using external capability switches).
Displays accommodate graphic symbols, printed text overlays, or real photographs.
Available in a wide variety of physical sizes and layout configurations.
Requires minimal operational training for users and communication partners.
Hardware Variations and Customization Parameters:
Size and Surface Area: Directly impacts device portability, spatial footprint, and physical targeting access.
Message Capacity: Ranges from single-message units to multi-message grid arrays.
Activation Mechanics: Configured based on user physical capabilities, including required activation pressure, switch angle, and spatial positioning.
Tool Interfacing: Ability to interface with auxiliary tools, such as external switch ports for single-switch or dual-switch scanning access.
Specific Device Examples:
littleMack / LITTLEmac: Single-message digitized voice output button.
GoTalk 32+ (manufactured by Attainment Company, Inc.): Multi-message digitized device featuring 32 main message buttons plus fixed functional grid buttons, built-in microphone (MIC), 5 distinct recording levels (1, 2, 3, 4, 5), carrying handle/backpack integration, visual overlays (e.g., MALL, Gift Card, Hi? Bye).
Additional Hardware Considerations:
Built-in volume control dials or controls to adjust output to background noise.
Wheelchair, desk, or floor mounting compatibility and hardware integration.
Architectural status: Determining whether the mid-tech tool acts as a stand-alone communication system or functions as a secondary component within a broader, multi-tiered AAC system.
High-Tech AAC Hardware and Software Specifications
General System Characteristics:
Computer- or tablet-based hardware platforms running dedicated AAC applications and specialized software.
Advanced functional and accessibility features:
Dual voice output options (digitized voice recording and text-to-speech synthesized output).
Integrated auditory input options and customizable auditory prompt feedback.
Fully customizable visual displays (adjustable background colors, high contrast ratios, spatial spacing).
Broad alternative access integration (eye gaze tracking, head tracking, touch screen sensitivity adjustments).
High-Tech Hardware Specifications:
Display Screen Size: Typically ranges from to diagonally.
System Weight: Influenced by protective outer cases, integrated amplified speakers, mounting plates, and external eye-gaze camera bars.
Alternative Access Capabilities: Native interfaces for switches, head-trackers, and optical eye-gaze systems.
Portability and Mounting: Specialized carrying handles, shoulder straps, and wheelchair mounting brackets.
Touch Screen Sensitivity: Programmable settings to accommodate tremors, spasticity, or drag touch patterns.
High-Tech Software Features:
System Programming and Customization: Custom modification of font type, font size, button color, background color, grid size, spatial spacing, voice selection, speech output rate, grammatical auto-inflection rules, and button visibility.
Vocabulary Organization: Integration of robust language options that facilitate Spontaneous Novel Utterance Generation (SNUG).
Voice Output Options: High-fidelity digitized human speech recordings and algorithmic synthesized text-to-speech engines.
Display Navigation: Dynamic display navigation linking main page sets, semantic sub-categories, core vocabulary, and topic pages.
High-Tech Software Display Formats
Grid-Based Displays:
Schematic: Organized according to specific routines, events, or environmental activity settings.
Semantic-Syntactic: Organized according to grammatical parts of speech and syntactical rules (e.g., subject pronouns, action verbs, descriptors, prepositions).
Taxonomic: Organized by semantic categories (e.g., food, animals, feelings, places).
Alphabetical: Arranged in sequential A-to-Z order for literate AAC users.
Chronological: Arranged according to temporal order or sequence of events.
Common Functional Grid Elements: Home controls, social greetings, core verbs (want, like, need, get, come, think, do), core pronouns (I, you, we, they, he, it), modifiers (+er, +est), math keypads (), quick pre-programmed phrases, punctuation keys, and navigation icons.
Visual Scene Display (VSD):
Employs contextually rich photographs or visual depictions of complete scenes, environments, or events.
Embedded with interactive screen regions known as hotspots that trigger speech output when tapped.
Scope of Communicative Purpose and Environment
Universal Access Rule: AAC systems must be physically present and accessible to the user at all times.
The Communication World Model:
Places: Home, school, work, retail stores, restaurants, medical offices, and community environments.
People: Family members, teachers, personal care assistants, doctors, emergency service personnel, and community workers.
Reasons for Communication: Autonomous decision-making, initiating social interactions, making requests, engaging in extended conversations, gaining access to healthcare, and sharing personal information.
Case Study: Implementation for Patient RA
Assessment Triad: Comprehensive clinical evaluation evaluating the interaction between The Individual, Their Communication Partners, and Their Environment.
System Architecture:
Primary System: High-tech AAC device for primary dynamic communication needs.
Secondary System: Mid-tech AAC device for secondary functional environments.
Environmental Tool: No-tech tool (lite-tech paper boards) for environmental modeling by communication partners.
Feature Rationale Matrix:
Voice Output: Provides vital auditory feedback to the user; enhances interactive conversational flow.
Synthesized Speech: Allows all spoken words to be generated dynamically without requiring manual pre-recording of individual button audio.
Message Window: Displays text/symbols as they are selected, encouraging the construction of multi-word phrases and complex sentences.
Extensive Symbol Set: Grants unrestricted access to extensive vocabulary sets without arbitrary limits.
Core/Fringe Template: Utilizes a pre-set, structured system combining high-frequency core words with category-specific fringe words to enhance language development.
Grammar Support: Supports learning of syntax and morphology via automatic rule assistance.
Color Coding: Categorizes parts of speech and word types to increase visual search speed and communication rate.
Pre-programmed Phrases: Guarantees instant access to high-frequency or emergency statements.
Keyboard with Word Prediction: Facilitates message generation using a standard QWERTY layout combined with predictive word algorithms to increase typing speed.
Dynamic Display: Allows fluid navigation through a multi-tiered, robust language system.
Overlay Backup: Prevents page sets from being lost or deleted; provides easy duplication for printed lite-tech paper boards.
Functional Communication Goals for Patient RA
Goal 1: Express feelings or state of being.
Estimated Completion Time: 2 weeks.
Classification: Short-Term Goal (Yes), Long-Term Goal (No).
Goal 2: Call for help from an unfamiliar person.
Estimated Completion Time: 1 month.
Classification: Short-Term Goal (Yes), Long-Term Goal (No).
Goal 3: Engage in social communication exchanges with a familiar person.
Estimated Completion Time: 1 month.
Classification: Short-Term Goal (Yes), Long-Term Goal (No).
Goal 4: Communicate physical needs and emotional status to a support person.
Estimated Completion Time: > 3\text{ months}.
Classification: Short-Term Goal (No), Long-Term Goal (Yes).
Goal 5: Convey a functional message in lieu of a challenging behavior.
Estimated Completion Time: > 3\text{ months}.
Classification: Short-Term Goal (No), Long-Term Goal (Yes).
Standardized Prompt Hierarchy in AAC
I (Independent): The AAC user completes the communication act entirely on their own without external assistance.
Vpp (Visual Point Prompt): The communication partner (CP) points to the general vicinity of the target button or directly at the target location.
Vb (Verbal Prompt): The CP describes the target button, tells the user what to select, or verbally encourages device use.
Wv (Written Visual Prompt): The CP displays printed words, written text, or graphic pictures to show the target to the user.
M (Modeling): The CP demonstrates the selection by pointing to or activating the target location on the device while communicating.
Ppa (Partial Physical Assistance): The CP offers minimal physical support to the user, such as guiding movement at the elbow.
HuH (Hand Under Hand): The CP provides complete physical assistance by placing their hand under the user's hand to guide them to the target button.