Redefining Machine Simultaneous Interpretation: From Incremental Translation to Human-Like Strategies

Qianen Zhang, Zeyu Yang, Satoshi Nakamura


Abstract
Simultaneous Machine Translation (SiMT) requires high-quality translations under strict real-time constraints, which traditional policies with only READ/WRITE actions cannot fully address. We extend the action space of SiMT with four adaptive actions: **Sentence_Cut**, **Drop**, **Partial_Summarization** and **Pronominalization**, which enable real-time restructuring, omission, and simplification while preserving semantic fidelity. We adapt these actions in a large language model (LLM) framework and construct training references through action-aware prompting. To evaluate both quality and word-level monotonicity, we further develop a latency-aware TTS pipeline that maps textual outputs to speech with realistic timing. Experiments on the ACL60/60 English-Chinese, English-German and English-Japanese benchmarks show that our framework consistently improves semantic metrics and achieves lower delay compared to reference translations and salami-based baselines. Notably, combining **Drop** and **Sentence_Cut** leads to consistent improvements in the balance between fluency and latency. These results demonstrate that enriching the action space of LLM-based SiMT provides a promising direction for bridging the gap between human and machine interpretation.
Anthology ID:
2026.findings-acl.611
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
12554–12577
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.611/
DOI:
Bibkey:
Cite (ACL):
Qianen Zhang, Zeyu Yang, and Satoshi Nakamura. 2026. Redefining Machine Simultaneous Interpretation: From Incremental Translation to Human-Like Strategies. In Findings of the Association for Computational Linguistics: ACL 2026, pages 12554–12577, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Redefining Machine Simultaneous Interpretation: From Incremental Translation to Human-Like Strategies (Zhang et al., Findings 2026)
Copy Citation:
PDF:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.611.pdf
Checklist:
 2026.findings-acl.611.checklist.pdf