Description and Discussion on DCASE 2022 Challenge Task 2: Unsupervised Anomalous Sound Detection for Machine Condition Monitoring Applying Domain Generalization Techniques

TL;DR

This paper discusses the DCASE 2022 Challenge Task 2, focusing on unsupervised anomalous sound detection for machine monitoring, emphasizing domain generalization techniques to handle unknown domain shifts without prior domain labels.

Contribution

It introduces a new challenge task emphasizing domain generalization for ASD, analyzing 81 submissions to identify effective techniques for unknown domain shifts.

Findings

Domain-mixing-based approaches for generalized representations

Domain-classification-based approaches for improved detection

Analysis of 81 submissions reveals effective domain generalization strategies

Abstract

We present the task description and discussion on the results of the DCASE 2022 Challenge Task 2: ``Unsupervised anomalous sound detection (ASD) for machine condition monitoring applying domain generalization techniques''. Domain shifts are a critical problem for the application of ASD systems. Because domain shifts can change the acoustic characteristics of data, a model trained in a source domain performs poorly for a target domain. In DCASE 2021 Challenge Task 2, we organized an ASD task for handling domain shifts. In this task, it was assumed that the occurrences of domain shifts are known. However, in practice, the domain of each sample may not be given, and the domain shifts can occur implicitly. In 2022 Task 2, we focus on domain generalization techniques that detects anomalies regardless of the domain shifts. Specifically, the domain of each sample is not given in the test data and only one threshold is allowed for all domains. Analysis of 81 submissions from 31 teams revealed two remarkable types of domain generalization techniques: 1) domain-mixing-based approach that obtains generalized representations and 2) domain-classification-based approach that explicitly or implicitly classifies different domains to improve detection performance for each domain.