Understanding and Bridging the Modality Gap for Speech Translation
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Abstract (arXiv)
How to achieve better end-to-end speech translation (ST) by leveraging (text) machine translation (MT) data? Among various existing techniques, multi-task learning is one of the effective ways to share knowledge between ST and MT in which additional MT data can help to learn source-to-target mapping. However, due to the differences between speech and text, there is always a gap between ST and MT. In this paper, we first aim to understand this modality gap from the target-side representation differences, and link the modality gap to another well-known problem in neural machine translation: exposure bias. We find that the modality gap is relatively small during training except for some difficult cases, but keeps increasing during inference due to the cascading effect. To address these problems, we propose the Cross-modal Regularization with Scheduled Sampling (Cress) method. Specifically, we regularize the output predictions of ST and MT, whose target-side contexts are derived by sampling between ground truth words and self-generated words with a varying probability. Furthermore, we introduce token-level adaptive training which assigns different training weights to target tokens to handle difficult cases with large modality gaps. Experiments and analysis show that our approach effectively bridges the modality gap, and achieves promising results in all eight directions of the MuST-C dataset.
Key facts. Cited by 15 papers in the map (data through 7 Oct 2026). Builds on 59 of its 86 references that are in the map. First posted on arXiv 15 May 2023.
Builds on
59 of 86 references.
References · 59
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38 more
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50 most cited of 59 All 59 (JSON)
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Citing papers per year: 2023: 9; 2024: 4; 2025: 2.
15 papers.
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- 2023CMOT: Cross-modal Mixup via Optimal Transport for Speech Translationcited by 22
- 2024Pushing the Limits of Zero-shot End-to-End Speech Translationcited by 14
- 2025Understanding the Modality Gap: An Empirical Study on the Speech-Text Alignment Mechanism of Large Speech Language Modelscited by 10
- 2023Tuning Large language model for End-to-end Speech Translationcited by 9
- 2023DASpeech: Directed Acyclic Transformer for Fast and High-quality Speech-to-Speech Translationcited by 9
- 2023Modality Adaption or Regularization? A Case Study on End-to-End Speech Translationcited by 6
- 2023An Empirical Study of Consistency Regularization for End-to-End Speech-to-Text Translationcited by 6
- 2023Bridging the Gap between Synthetic and Authentic Images for Multimodal Machine Translationcited by 6
- 2023Unified Segment-to-Segment Framework for Simultaneous Sequence Generationcited by 6
- 2023Rethinking and Improving Multi-task Learning for End-to-end Speech Translationcited by 6
- 2024Can We Achieve High-quality Direct Speech-to-Speech Translation without Parallel Speech Data?cited by 4
- 2024CoSTA: Code-Switched Speech Translation using Aligned Speech-Text Interleavingcited by 4
- 2025Understanding the Modality Gap: An Empirical Study on the Speech-Text Alignment Mechanism of Large Speech Language Models14 Oct 2025
- 2025Speech Translation Refinement using Large Language Models25 Jan 2025
- 2024CoSTA: Code-Switched Speech Translation using Aligned Speech-Text Interleaving16 Jun 2024
- 2024CTC-based Non-autoregressive Textless Speech-to-Speech Translation11 Jun 2024
- 2024Can We Achieve High-quality Direct Speech-to-Speech Translation without Parallel Speech Data?11 Jun 2024
- 2024Pushing the Limits of Zero-shot End-to-End Speech Translation16 Feb 2024
- 2023Rethinking and Improving Multi-task Learning for End-to-end Speech Translation7 Nov 2023
- 2023Unified Segment-to-Segment Framework for Simultaneous Sequence Generation27 Oct 2023
- 2023Bridging the Gap between Synthetic and Authentic Images for Multimodal Machine Translation20 Oct 2023
- 2023DASpeech: Directed Acyclic Transformer for Fast and High-quality Speech-to-Speech Translation11 Oct 2023
- 2023Tuning Large language model for End-to-end Speech Translation3 Oct 2023
- 2023Bridging the Gaps of Both Modality and Language: Synchronous Bilingual CTC for Speech Translation and Speech Recognition21 Sep 2023
- 2023CMOT: Cross-modal Mixup via Optimal Transport for Speech Translationcited by 22
- 2024Pushing the Limits of Zero-shot End-to-End Speech Translationcited by 14
- 2025Understanding the Modality Gap: An Empirical Study on the Speech-Text Alignment Mechanism of Large Speech Language Modelscited by 10
- 2023Tuning Large language model for End-to-end Speech Translationcited by 9
- 2023DASpeech: Directed Acyclic Transformer for Fast and High-quality Speech-to-Speech Translationcited by 9
- 2023Modality Adaption or Regularization? A Case Study on End-to-End Speech Translationcited by 6
- 2023An Empirical Study of Consistency Regularization for End-to-End Speech-to-Text Translationcited by 6
- 2023Bridging the Gap between Synthetic and Authentic Images for Multimodal Machine Translationcited by 6
- 2023Unified Segment-to-Segment Framework for Simultaneous Sequence Generationcited by 6
- 2023Rethinking and Improving Multi-task Learning for End-to-end Speech Translationcited by 6
- 2024Can We Achieve High-quality Direct Speech-to-Speech Translation without Parallel Speech Data?cited by 4
- 2024CoSTA: Code-Switched Speech Translation using Aligned Speech-Text Interleavingcited by 4
12 most cited of 15 All 15 (JSON)
- 2025Understanding the Modality Gap: An Empirical Study on the Speech-Text Alignment Mechanism of Large Speech Language Models14 Oct 2025
- 2025Speech Translation Refinement using Large Language Models25 Jan 2025
- 2024CoSTA: Code-Switched Speech Translation using Aligned Speech-Text Interleaving16 Jun 2024
- 2024CTC-based Non-autoregressive Textless Speech-to-Speech Translation11 Jun 2024
- 2024Can We Achieve High-quality Direct Speech-to-Speech Translation without Parallel Speech Data?11 Jun 2024
- 2024Pushing the Limits of Zero-shot End-to-End Speech Translation16 Feb 2024
- 2023Rethinking and Improving Multi-task Learning for End-to-end Speech Translation7 Nov 2023
- 2023Unified Segment-to-Segment Framework for Simultaneous Sequence Generation27 Oct 2023
- 2023Bridging the Gap between Synthetic and Authentic Images for Multimodal Machine Translation20 Oct 2023
- 2023DASpeech: Directed Acyclic Transformer for Fast and High-quality Speech-to-Speech Translation11 Oct 2023
- 2023Tuning Large language model for End-to-end Speech Translation3 Oct 2023
- 2023Bridging the Gaps of Both Modality and Language: Synchronous Bilingual CTC for Speech Translation and Speech Recognition21 Sep 2023
12 newest of 15 All 15 (JSON)