MoLEx: Mixture of LoRA Experts in Speech Self-Supervised Models for Audio Deepfake Detection

Fuente: arXiv
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Main Authors: Pan, Zihan, Bhupendra, Sailor Hardik, Wu, Jinyang
Format: Preprint
Published: 2025
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author Pan, Zihan
Bhupendra, Sailor Hardik
Wu, Jinyang
author_facet Pan, Zihan
Bhupendra, Sailor Hardik
Wu, Jinyang
contents While self-supervised learning (SSL)-based models have boosted audio deepfake detection accuracy, fully finetuning them is computationally expensive. To address this, we propose a parameter-efficient framework that combines Low-Rank Adaptation with a Mixture-of-Experts router, called Mixture of LoRA Experts (MoLEx). It preserves pre-trained knowledge of SSL models while efficiently finetuning only selected experts, reducing training costs while maintaining robust performance. The observed utility of experts during inference shows the router reactivates the same experts for similar attacks but switches to other experts for novel spoofs, confirming MoLEx's domain-aware adaptability. MoLEx additionally offers flexibility for domain adaptation by allowing extra experts to be trained without modifying the entire model. We mainly evaluate our approach on the ASVSpoof 5 dataset and achieve the state-of-the-art (SOTA) equal error rate (EER) of 5.56% on the evaluation set without augmentation.
format Preprint
id arxiv_https___arxiv_org_abs_2509_09175
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle MoLEx: Mixture of LoRA Experts in Speech Self-Supervised Models for Audio Deepfake Detection
Pan, Zihan
Bhupendra, Sailor Hardik
Wu, Jinyang
Sound
Multimedia
While self-supervised learning (SSL)-based models have boosted audio deepfake detection accuracy, fully finetuning them is computationally expensive. To address this, we propose a parameter-efficient framework that combines Low-Rank Adaptation with a Mixture-of-Experts router, called Mixture of LoRA Experts (MoLEx). It preserves pre-trained knowledge of SSL models while efficiently finetuning only selected experts, reducing training costs while maintaining robust performance. The observed utility of experts during inference shows the router reactivates the same experts for similar attacks but switches to other experts for novel spoofs, confirming MoLEx's domain-aware adaptability. MoLEx additionally offers flexibility for domain adaptation by allowing extra experts to be trained without modifying the entire model. We mainly evaluate our approach on the ASVSpoof 5 dataset and achieve the state-of-the-art (SOTA) equal error rate (EER) of 5.56% on the evaluation set without augmentation.
title MoLEx: Mixture of LoRA Experts in Speech Self-Supervised Models for Audio Deepfake Detection
topic Sound
Multimedia
url https://arxiv.org/abs/2509.09175