titleWhisper Hallucination Detection and Mitigation via Hidden Representation Steering and Sparse AutoEncoders
authorsGeorgii Aparin, Vadim Popov, Tasnima Sadekova, Assel Yermekova
date2026-06-05
venuearXiv (preprint, not peer reviewed)
idarXiv:2606.07473
affiliationHUAWEI Noah's Ark Lab
upvotes14 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf
abstractWhisper, a widely adopted ASR model, is known to suffer from hallucinations - coherent transcriptions generated for non-speech audio entirely disconnected from the input. We investigate whether hallucinations can be detected and mitigated through Whisper's internal representations. We extract audio encoder activations and evaluate two representation spaces: raw Whisper activations and Sparse AutoEncoder (SAE) latents. We show that both spaces encode linearly separable hallucination-related information, with discriminative power concentrated in a sparse feature subset and increasing toward deeper encoder layers. We propose two steering strategies: activation-space steering and SAE latent-space steering. SAE-based steering reduces hallucination rate from 72.63% to 14.11% for Whisper small and from 86.88% to 27.33% for Whisper large-v3 on the full non-speech test set, with small WER degradation on speech data, approaching the performance of fine-tuning-based methods.

cite

@misc{aparin2026whisper,
  title={Whisper Hallucination Detection and Mitigation via Hidden Representation Steering and Sparse AutoEncoders},
  author={Georgii Aparin and Vadim Popov and Tasnima Sadekova and Assel Yermekova},
  year={2026},
  eprint={2606.07473},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2606.07473}
}