CTAL: Pre-training Cross-modal Transformer for Audio-and-Language Representations

Existing approaches for audio-language task-specific prediction focus on building complicated late-fusion mechanisms. However, these models face challenges of overfitting with limited labels and poor generalization. In this paper, we present a Cross-modal Transformer for Audio-and-Language, i.e., CTAL, which aims to learn the intra- and inter-modalities connections between audio and language through two proxy tasks from a large number of audio-and-language pairs: masked language modeling and masked cross-modal acoustic modeling. After fine-tuning our CTAL model on multiple downstream audio and-language tasks, we observe significant improvements on different tasks, including emotion classification, sentiment analysis, and speaker verification. Furthermore, we design a fusion mechanism in the fine-tuning phase, which allows CTAL to achieve better performance. Lastly, we conduct detailed ablation studies to demonstrate that both our novel cross-modality fusion component and audio language pre-training methods contribute to the promising results. The code and pretrained models are available at https://github.com/tal-al/CTAL_EMNLP2021.