I am currently a postdoctoral research fellow with Speech Lab, College of Computing and Data Science, at Nanyang Technological University, supervised by Prof. Eng Siong Chng.
Prior to joining NTU Speech Lab, I received my Ph.D. from School of Electronic and Electrical Engineering at Nanyang Technological University, under the supervision of Prof. Andy W. H. Khong (EEE, Nanyang Technological University) and Dr. Leibny Paola Garcia (CLSP, The Johns Hopkins Univerisity). Apart from my supervisors, I also work closely with Prof. Suzy J. Styles (NTU), Prof. Sanjeev Khudanpur (JHU), and Prof. Shinji Watanabe (CMU).

My research topics are:

• Spoken Language Recognition: Language identification and diarization

• Speech Recognition: Code-switching and multilingual speech recognition

• Large-scale Pre-trained Model: Speech/Audio-LLM and other LLM-based applications

📖 Educations

• 2018.08 - 2023.05, Ph.D., Nanyang Technological University.
  Thesis: Enhancing Spoken Language Identification and Diarization for Multilingual Speech
  Supervisors: Prof. Andy W. H. Khong (NTU) & Dr. Leibny Paola Garcia (JHU)
• 2017.08 - 2018.05, Ms.C., Nanyang Technological University.
• 2012.09 - 2016.07, B.Eng, Harbin Institute of Technology.
  Supervisor: Prof. Chenguang He

📝 Selected Publications (first/corresponding author)

• ACL Findings SpeechT-RAG: Reliable Depression Detection in LLMs with Retrieval-Augmented Generation Using Speech Timing Information, Xiangyu Zhang, Hexin Liu*, Qiquan Zhang, Beena Ahmed, Julien Epps.

• IEEE TASLP A Two-Stage LoRA Strategy for Expanding Language Capabilities in Multilingual ASR Models, Chin Yuen Kwok, Hexin Liu*, Jia Qi Yip, Sheng Li, Eng Siong Chng.

• IEEE TASLP Mamba in Speech: Towards an Alternative to Self-Attention, Xiangyu Zhang*, Qiquan Zhang*, Hexin Liu*, Tianyi Xiao, Xinyuan Qian, Beena Ahmed, Eliathamby Ambikairajah, Haizhou Li, Julien Epps.

• Preprint Aligning Speech to Languages to Enhance Code-switching Speech Recognition, Hexin Liu, Xiangyu Zhang, Leibny Paola Garcia, Andy W.H. Khong, Eng Siong Chng, Shinji Watanabe.

• ICASSP 2024 Enhancing Code-switching Speech Recognition with Interactive Language Biases, Hexin Liu, Leibny Paola Garcia, Xiangyu Zhang, Andy W.H. Khong, Sanjeev Khudanpur.

• ICASSP 2023 Reducing Language Confusion for Code-switching Speech Recognition with Token-level Language Diarization, Hexin Liu, Haihua Xu, Leibny Paola Garcia, Andy W.H. Khong, Yi He, Sanjeev Khudanpur.

• Interspeech 2023 MERLIon CCS Challenge: A English-Mandarin code-switching child-directed speech corpus for language identification and diarization, Victoria YH Chua*, Hexin Liu*, Leibny Paola Garcia, Fei Ting Woon, Jinyi Wong, Xiangyu Zhang, Sanjeev Khudanpur, Andy W.H. Khong, Justin Dauwels, Suzy J Styles.

• IEEE JSTSP Efficient self-supervised learning representations for spoken language identification, Hexin Liu, Leibny Paola Garcia, Andy W.H. Khong, Eng Siong Chng, Suzy J. Styles, Sanjeev Khudanpur.

• Odyssey 2022 Enhancing Language Identification using Dual-mode Model with Knowledge Distillation, Hexin Liu, Leibny Paola Garcia, Andy W.H. Khong, Justin Dauwels, Suzy J. Styles, Sanjeev Khudanpur.

• Interspeech 2022(Oral) PHO-LID: A Unified Model Incorporating Acoustic-Phonetic and Phonotactic Information for Language Identification, Hexin Liu, Leibny Paola Garcia, Andy W.H. Khong, Suzy J. Styles, Sanjeev Khudanpur.

• Interspeech 2021 End-to-end language diarization for bilingual code-switching speech, Hexin Liu, Leibny Paola Garcia, Xinyi Zhang, Justin Dauwels, Andy W.H. Khong, Sanjeev Khudanpur, Suzy J. Styles.

🧑‍🔬 Services

• Reviewer:  ICASSP(23-24), Interspeech(2022-24), ASRU(2022-24), SLT(2022-24), COLING(2024-25), IEEE TASLP, SPL, ESWA
• Session Chair:  Interspeech (2023), APSIPA-TPC (2025-27), IALP (2024)
• Others:  Mentor in IEEE SLT 2022 Hackthon

💻 Work Experiences

• 2022.08 - 2023.01, Research Scientist Intern, Bytedance AI Lab, Singapore.
• 2023.04 - 2023.08, Research Associate, Delta-NTU Corp Lab, Nanyang Technological University.
• 2023.09 - now, Research Fellow, Speech Lab, Nanyang Technological University.

💬 Invited talks

• 2024.06，IEEE & APSIPA SG chapters joint Seminar: Emerging Trends and Innovations in Machine Learning and AI
  Automatic speech recognition with large language models [slides]