Turn-taking and Backchannel Prediction with Acoustic and Large Language Model Fusion
Jinhan Wang, Long Chen, Aparna Khare, Anirudh Raju, Pranav Dheram, Di He, Minhua Wu, Andreas Stolcke, Venkatesh Ravichandran
TL;DR
The paper addresses predicting turn-taking and backchannel locations in spoken dialogue by fusing HuBERT-based acoustic representations with LLM embeddings (GPT-2 and RedPajama). It introduces a late-fusion framework with two configurations (Opt1/Opt2) and a novel multi-task instruction-fine-tuning scheme to leverage task descriptions and dialogue history, optimizing $P(Y|X^A,X^L)$ for $Y \in \{Continuing Speech, Backchannel, Turn-taking\}$. On Switchboard, fusion approaches outperform single-modality baselines, with RedPajama plus instruction tuning and history achieving the strongest performance (average AUC around 0.88). The results demonstrate that combining acoustic signals with LLM-based language understanding yields more natural, responsive human-agent dialogue as evidenced by improvements in turn-taking and backchannel prediction.
Abstract
We propose an approach for continuous prediction of turn-taking and backchanneling locations in spoken dialogue by fusing a neural acoustic model with a large language model (LLM). Experiments on the Switchboard human-human conversation dataset demonstrate that our approach consistently outperforms the baseline models with single modality. We also develop a novel multi-task instruction fine-tuning strategy to further benefit from LLM-encoded knowledge for understanding the tasks and conversational contexts, leading to additional improvements. Our approach demonstrates the potential of combined LLMs and acoustic models for a more natural and conversational interaction between humans and speech-enabled AI agents.
