Noise Supervised Contrastive Learning and Feature-Perturbed for Anomalous Sound Detection

Unsupervised anomalous sound detection aims to detect unknown anomalous sounds by training a model using only normal audio data. Despite advancements in self-supervised methods, the issue of frequent false alarms when handling samples of the same type from different machines remains unresolved. This paper introduces a novel training technique called one-stage supervised contrastive learning (OS-SCL), which significantly addresses this problem by perturbing features in the embedding space and employing a one-stage noisy supervised contrastive learning approach. On the DCASE 2020 Challenge Task 2, it achieved 94.64\% AUC, 88.42\% pAUC, and 89.24\% mAUC using only Log-Mel features. Additionally, a time-frequency feature named TFgram is proposed, which is extracted from raw audio. This feature effectively captures critical information for anomalous sound detection, ultimately achieving 95.71\% AUC, 90.23\% pAUC, and 91.23\% mAUC. The source code is available at: \underline{www.github.com/huangswt/OS-SCL}.

OR-Gate: A Noisy Label Filtering Method for Speaker Verification

The deep learning models used for speaker verification are heavily dependent on large-scale data and correct labels. However, noisy (wrong) labels often occur, which deteriorates the system's performance. Unfortunately, there are relatively few studies in this area. In this paper, we propose a method to gradually filter noisy labels out at the training stage. We compare the network predictions at different training epochs with ground-truth labels, and select reliable (considered correct) labels by using the OR gate mechanism like that in logic circuits. Therefore, our proposed method is named as OR-Gate. We experimentally demonstrated that the OR-Gate can effectively filter noisy labels out and has excellent performance.