  Recent work on speech representation models jointly pre-trained with text has
demonstrated the potential of improving speech representations by encoding
speech and text in a shared space. In this paper, we leverage such shared
representations to address the persistent challenge of limited data
availability in spoken language understanding tasks. By employing a pre-trained
speech-text model, we find that models fine-tuned on text can be effectively
transferred to speech testing data. With as little as 1 hour of labeled speech
data, our proposed approach achieves comparable performance on spoken language
understanding tasks (specifically, sentiment analysis and named entity
recognition) when compared to previous methods using speech-only pre-trained
models fine-tuned on 10 times more data. Beyond the proof-of-concept study, we
also analyze the latent representations. We find that the bottom layers of
speech-text models are largely task-agnostic and align speech and text
representations into a shared space, while the top layers are more
task-specific.
