One Does Not Simply 'Mm-hmm': Exploring Backchanneling in the AAC Micro-Culture

2025-06-21

AI Summary

This study investigates feedback behaviors—such as vocalizations (“um”), head nods, and other embodied cues—employed by individuals with speech and motor impairments using Augmentative and Alternative Communication (AAC) technologies, contrasting them with neurotypical hearing users’ practices to uncover emergent microcultures of communication in dyadic and mixed-user interactions. Method: Employing a qualitative, participatory approach, the research co-analyzed authentic interactional episodes through workshops and in-depth interviews involving four AAC users and four speech-language pathologists. Contribution/Results: It theoretically reframes AAC feedback as an embodied, collaborative microcultural practice for the first time. The study proposes three design principles—multimodality, contextual sensitivity, and timeliness—and identifies user-developed nonverbal feedback strategies. These findings advocate shifting AAC design from unimodal output toward multimodal, body-technology co-regulatory mechanisms that support natural conversational rhythm and intersubjective coordination.

Technology Category

• Humans and AI: Interaction Techniques and Devices
• Cognitive Modeling & Cognitive Systems: Social Cognition And Interaction
• Multiagent Systems: Agent Communication

Application Category

• User Modeling, Personalization and Recommendation: Practical large-scale studies of user experience
• Search and Retrieval-Augmented AI: Assisted, interactive, and conversational search
• Semantics and Knowledge: Data modeling to support human-machine intelligence, including LLMs agents, intelligent system behavior, explanations, and user-friendly interactions

Abstract

Backchanneling (e.g., "uh-huh", "hmm", a simple nod) encompasses a big part of everyday communication; it is how we negotiate the turn to speak, it signals our engagement, and shapes the flow of our conversations. For people with speech and motor impairments, backchanneling is limited to a reduced set of modalities, and their Augmentative and Alternative Communication (AAC) technology requires visual attention, making it harder to observe non-verbal cues of conversation partners. We explore how users of AAC technology approach backchanneling and create their own unique channels and communication culture. We conducted a workshop with 4 AAC users to understand the unique characteristics of backchanneling in AAC. We explored how backchanneling changes when pairs of AAC users communicate vs when an AAC user communicates with a non-AAC user. We contextualize these findings through four in-depth interviews with speech-language pathologists (SLPs). We conclude with a discussion about backchanneling as a micro-cultural practice, rethinking embodiment and mediation in AAC technology, and providing design recommendations for timely multi-modal backchanneling while respecting different communication cultures.

Problem

• Exploring backchanneling challenges in AAC users' communication
• Comparing backchanneling in AAC vs non-AAC user interactions
• Designing multi-modal backchanneling solutions for AAC technology

Innovation

• Workshop with AAC users exploring backchanneling
• Comparative study of AAC and non-AAC communication
• Design recommendations for multi-modal backchanneling