Compositional Audio Representation Learning
Sripathi Sridhar, Mark Cartwright
TL;DR
This work addresses the challenge of learning interpretable, source-centric representations for complex auditory scenes, moving beyond clip-level encodings. It introduces Compositional Audio Representation Learning (CARL), with supervised and unsupervised variants built around a frozen AudioMAE encoder, a slot-transformer that yields multiple source slots, a reconstruction decoder, and a slot-wise classifier, trained with a mixture of reconstruction and regularization losses. On the OST synthetic dataset, supervised CARL achieves the best performance, and unsupervised CARL shows that feature reconstruction and larger slot dimensions improve open-ended source discovery, while reconstruction targets and regularizers crucially shape generalization. The results suggest that supervised signals enhance interpretability and downstream performance, while unsupervised approaches require richer signals to close the gap, pointing to future work with partial labels, counts, natural language descriptions, or self-supervision to enable robust, source-level machine listening in real-world environments.
Abstract
Human auditory perception is compositional in nature -- we identify auditory streams from auditory scenes with multiple sound events. However, such auditory scenes are typically represented using clip-level representations that do not disentangle the constituent sound sources. In this work, we learn source-centric audio representations where each sound source is represented using a distinct, disentangled source embedding in the audio representation. We propose two novel approaches to learning source-centric audio representations: a supervised model guided by classification and an unsupervised model guided by feature reconstruction, both of which outperform the baselines. We thoroughly evaluate the design choices of both approaches using an audio classification task. We find that supervision is beneficial to learn source-centric representations, and that reconstructing audio features is more useful than reconstructing spectrograms to learn unsupervised source-centric representations. Leveraging source-centric models can help unlock the potential of greater interpretability and more flexible decoding in machine listening.
