A Multi-Task, Multi-Modal Approach for Predicting Categorical and Dimensional Emotions
Alex-Răzvan Ispas, Théo Deschamps-Berger, Laurence Devillers
TL;DR
This work tackles speech emotion recognition by jointly predicting categorical labels and dimensional valence/arousal in spontaneous conversations. It introduces a multi-task, multi-modal architecture that fuses acoustic (HuBERT-large) and linguistic (DeBERTaV3-large) features via two cross-attention layers and learnable bridge tokens, with a Random Modality Masking strategy to balance uni- and multi-modal learning. The multi-task objective combines categorical cross-entropy with CCC-based losses for valence and arousal, leading to improved valence performance (CCC up to $0.748$) and competitive categorical accuracy (WAR ~74%). The findings demonstrate that cross-regularisation between tasks and bridge-token-based fusion significantly benefits emotion estimation, offering a robust approach for SER in naturalistic data and establishing a path for further refinements in token design and regression strategies.
Abstract
Speech emotion recognition (SER) has received a great deal of attention in recent years in the context of spontaneous conversations. While there have been notable results on datasets like the well known corpus of naturalistic dyadic conversations, IEMOCAP, for both the case of categorical and dimensional emotions, there are few papers which try to predict both paradigms at the same time. Therefore, in this work, we aim to highlight the performance contribution of multi-task learning by proposing a multi-task, multi-modal system that predicts categorical and dimensional emotions. The results emphasise the importance of cross-regularisation between the two types of emotions. Our approach consists of a multi-task, multi-modal architecture that uses parallel feature refinement through self-attention for the feature of each modality. In order to fuse the features, our model introduces a set of learnable bridge tokens that merge the acoustic and linguistic features with the help of cross-attention. Our experiments for categorical emotions on 10-fold validation yield results comparable to the current state-of-the-art. In our configuration, our multi-task approach provides better results compared to learning each paradigm separately. On top of that, our best performing model achieves a high result for valence compared to the previous multi-task experiments.
