2025
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OmniCharacter: Towards Immersive Role-Playing Agents with Seamless Speech-Language Personality Interaction
Haonan Zhang
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Run Luo
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Xiong Liu
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Yuchuan Wu
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Ting-En Lin
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Pengpeng Zeng
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Qiang Qu
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Feiteng Fang
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Min Yang
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Lianli Gao
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Jingkuan Song
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Fei Huang
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Yongbin Li
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Role-Playing Agents (RPAs), benefiting from large language models, is an emerging interactive AI system that simulates roles or characters with diverse personalities. However, existing methods primarily focus on mimicking dialogues among roles in textual form, neglecting the role’s voice traits (e.g., voice style and emotions) as playing a crucial effect in interaction, which tends to be more immersive experiences in realistic scenarios. Towards this goal, we propose OmniCharacter, a first seamless speech-language personality interaction model to achieve immersive RPAs with low latency. Specifically, OmniCharacter enables agents to consistently exhibit role-specific personality traits and vocal traits throughout the interaction, enabling a mixture of speech and language responses. To align the model with speech-language scenarios, we construct a dataset named OmniCharacter-10K, which involves more distinctive characters (20), richly contextualized multi-round dialogue (10K), and dynamic speech response (135K). Experimental results showcase that our method yields better responses in terms of both content and style compared to existing RPAs and mainstream speech-language models, with a response latency as low as 289ms.
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Sticking to the Mean: Detecting Sticky Tokens in Text Embedding Models
Kexin Chen
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Dongxia Wang
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Yi Liu
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Haonan Zhang
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Wenhai Wang
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Despite the widespread use of Transformer-based text embedding models in NLP tasks, surprising “sticky tokens” can undermine the reliability of embeddings. These tokens, when repeatedly inserted into sentences, pull sentence similarity toward a certain value, disrupting the normal distribution of embedding distances and degrading downstream performance. In this paper, we systematically investigate such anomalous tokens, formally defining them and introducing an efficient detection method, Sticky Token Detector (STD), based on sentence and token filtering. Applying STD to 40 checkpoints across 14 model families, we discover a total of 868 sticky tokens. Our analysis reveals that these tokens often originate from special or unused entries in the vocabulary, as well as fragmented subwords from multilingual corpora. Notably, their presence does not strictly correlate with model size or vocabulary size. We further evaluate how sticky tokens affect downstream tasks like clustering and retrieval, observing significant performance drops of up to 50%. Through attention-layer analysis, we show that sticky tokens disproportionately dominate the model’s internal representations, raising concerns about tokenization robustness. Our findings show the need for better tokenization strategies and model design to mitigate the impact of sticky tokens in future text embedding applications.
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MMEvol: Empowering Multimodal Large Language Models with Evol-Instruct
Run Luo
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Haonan Zhang
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Longze Chen
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Ting-En Lin
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Xiong Liu
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Yuchuan Wu
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Min Yang
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Yongbin Li
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Minzheng Wang
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Pengpeng Zeng
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Lianli Gao
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Heng Tao Shen
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Yunshui Li
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Hamid Alinejad-Rokny
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Xiaobo Xia
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Jingkuan Song
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Fei Huang
Findings of the Association for Computational Linguistics: ACL 2025
The development of Multimodal Large Language Models (MLLMs) has seen significant progress, driven by increasing demands across various fields (e.g., multimodal agents, embodied intelligence). While model-driven approaches aim to enhance MLLM capabilities through diverse architectures, their performance gains have become increasingly marginal. In contrast, data-driven methods, which scale up image-text instruction datasets, have proven more effective but face challenges related to limited data diversity and complexity. The absence of high-quality instruction data remains a major bottleneck in MLLM development. To address this issue, we propose , a novel multimodal instruction data evolution framework. This framework iteratively enhances data quality through a refined combination of fine-grained perception, cognitive reasoning, and interaction evolution, generating a more complex and diverse image-text instruction dataset that significantly improves MLLM capabilities. Starting with an initial dataset, SEED-163K, we employ to systematically expand instruction diversity, extend visual reasoning steps to improve cognitive abilities, and extract fine-grained visual details to enhance understanding and robustness. To rigorously evaluate our approach, we conduct extensive qualitative analysis and quantitative experiments across 13 vision-language tasks. Compared to baseline models trained on the original seed dataset, our method achieves an average accuracy improvement of 3.1 percentage points. Moreover, our approach attains state-of-the-art (SOTA) performance in nine tasks while using significantly less data than existing state-of-the-art models.