SLM-S2ST: A multimodal language model for direct speech-to-speech translation

Yuxuan Hu; Haibin Wu; Ruchao Fan; Xiaofei Wang; Heng Lu; Yao Qian; Jinyu Li

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arXiv · 2506.04392

SLM-S2ST: A multimodal language model for direct speech-to-speech translation

Yuxuan Hu·Haibin Wu·Ruchao Fan·Xiaofei Wang·Heng Lu·Yao Qian·Jinyu Li

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Abstract

Speech-aware language models (LMs) have demonstrated capabilities in understanding spoken language while generating text-based responses. However, enabling them to produce speech output efficiently and effectively remains a challenge. In this paper, we present SLM-S2ST, a multimodal LM for direct speech-to-speech translation (S2ST), built on the open-source Phi4-MM model. SLM-S2ST extends its predecessor by generating translated speech using an audio transformer head that predicts audio tokens with a delay relative to text tokens, followed by a streaming vocoder for waveform synthesis. Our experimental results on the CVSS-C dataset demonstrate SLM-S2ST's superior performance, significantly surpassing existing baseline models trained on the same dataset. Furthermore, when we scale up the training data and the model size, SLM-S2ST reaches on-par performance with the current SOTA model.

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BibTeX RIS

Yuxuan Hu, Haibin Wu, Ruchao Fan, Xiaofei Wang, Heng Lu, Yao Qian, Jinyu Li. 2026-02-11. SLM-S2ST: A multimodal language model for direct speech-to-speech translation. https://arxiv.org/abs/2506.04392

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