Interactions with virtual assistants typically start with a trigger phrase followed by a command. In this work, we explore the possibility of making these interactions more natural by eliminating the need for a trigger phrase. Our goal is to determine whether a user addressed the virtual assistant based on signals obtained from the streaming audio recorded by the device microphone. We address this task by combining 1-best hypotheses and decoder signals from an automatic speech recognition system with acoustic representations from an audio encoder as input features to a large language model (LLM). In particular, we are interested in data and resource efficient systems that require only a small amount of training data and can operate in scenarios with only a single frozen LLM available on a device. For this reason, our model is trained on 80k or less examples of multimodal data using a combination of low-rank adaptation and prefix tuning. We compare the proposed system to unimodal baselines and show that the multimodal approach achieves lower equal-error-rates (EERs), while using only a fraction of the training data. We also show that low-dimensional specialized audio representations lead to lower EERs than high-dimensional general audio representations.
@article{arxiv.2312.03632,
title = {Multimodal Data and Resource Efficient Device-Directed Speech Detection with Large Foundation Models},
author = {Dominik Wagner and Alexander Churchill and Siddharth Sigtia and Panayiotis Georgiou and Matt Mirsamadi and Aarshee Mishra and Erik Marchi},
journal= {arXiv preprint arXiv:2312.03632},
year = {2023}
}