Why Can’t They Remember? Uncovering Representation and Retrieval Bottlenecks in Multi-Turn Acoustic Memory

Yang Xiao, Siyi Wang, Han Yin, Hong Jia, Vidhyasaharan Sethu, Eun-Jung Holden, Ting Dang


Abstract
Large audio language models (LALMs) process both speech and environmental acoustic cues, yet struggle to retain non-speech information across multi-turn interactions. The performance gap between semantic (speech) and acoustic (non-speech) understanding remains poorly understood, and the underlying mechanisms of representation and retrieval are still unclear. This work introduces EnvMem, a controlled multi-turn benchmark designed to study this gap and identify the root causes of failures at the representation (i.e., latent embeddings) and retrieval levels (i.e., attention allocation). We further conduct post-hoc interventions to probe representational structure and attention dynamics. Our results reveal representational trajectory drift as the key failure mode, while showing that attention allocation tested here does not consistently explain the degradation. Overall, we provide a systematic framework for analyzing and improving non-linguistic memory in long-context LALMs, shedding light on future data and training design for robust acoustic memory modeling.
Anthology ID:
2026.emnlp-main.847
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
19641–19655
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URL:
https://aclanthology.org/2026.emnlp-main.847/
DOI:
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Cite (ACL):
Yang Xiao, Siyi Wang, Han Yin, Hong Jia, Vidhyasaharan Sethu, Eun-Jung Holden, and Ting Dang. 2026. Why Can’t They Remember? Uncovering Representation and Retrieval Bottlenecks in Multi-Turn Acoustic Memory. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 19641–19655, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Why Can’t They Remember? Uncovering Representation and Retrieval Bottlenecks in Multi-Turn Acoustic Memory (Xiao et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.847.pdf