Joint Analysis of Acoustic Scenes and Sound Events Based on Semi-Supervised Training of Sound Events With Partial Labels
Abstract
Annotating time boundaries of sound events is labor-intensive, limiting the scalability of strongly supervised learning in audio detection. To reduce annotation costs, weakly-supervised learning with only clip-level labels has been widely adopted. As an alternative, partial label learning offers a cost-effective approach, where a set of possible labels is provided instead of exact weak annotations. However, partial label learning for audio analysis remains largely unexplored. Motivated by the observation that acoustic scenes provide contextual information for constructing a set of possible sound events, we utilize acoustic scene information to construct partial labels of sound events. On the basis of this idea, in this paper, we propose a multitask learning framework that jointly performs acoustic scene classification and sound event detection with partial labels of sound events. While reducing annotation costs, weakly-supervised and partial label learning often suffer from decreased detection performance due to lacking the precise event set and their temporal annotations. To better balance between annotation cost and detection performance, we also explore a semi-supervised framework that leverages both strong and partial labels. Moreover, to refine partial labels and achieve better model training, we propose a label refinement method based on self-distillation for the proposed approach with partial labels.