Chi-Chang Lee

I earned both my Bachelor’s and Master’s degrees in Engineering Science and Computer Science from National Taiwan University, where I worked closely with Prof. Yu Tsao and Prof. Hsin-Min Wang. Before 2023, my research primarily centered on machine learning for audio and speech modalities, especially Speech-to-Text systems and task-aware front-end processing for downstream audio applications. I focused on improving robustness to diverse acoustic environments (ICLR'23 & ASRU'23) and on how such robustness can be continually learned and adapted over time (Interspeech'20 and Interspeech'22).

In 2023, I have been honored to begin collaborating with the Improbable AI Lab at MIT CSAIL, led by Prof. Pulkit Agrawal, and shifted my primary research focus to Embodied AI, particularly Reinforcement Learning (RL). My current work investigates how, under a finite interaction budget, a robotic agent can learn to distinguish heuristic signals from the true task objective while still optimizing for the real but sparse success outcomes. This collaboration has led to two papers: one on the real-world deployment of locomotion policies (ICRA'24), and another on an advanced RL algorithm that achieves consistent gains on 31 robotic tasks (NeurIPS'24).

       

  Experience

Research Collaborator Jul. 2023 – present
Improbable AI Lab at Massachusetts Institute of Technology
Advisor: Pulkit Agrawal
Research Assistant Mar. 2019 – Mar. 2024
Bio-ASP Lab at Academia Sinica CITI, Taiwan
Advisor: Yu Tsao
Visiting Researcher Nov. 2022 – Feb. 2023
Yamagishi Laboratory at National Institute of Informatics, Japan
Advisor: Prof. Junichi Yamagishi


  Publications in Robot Learning and Embodied AI
(∗ indicates equal contribution)

Optimal robot learning under finite interaction budgets - In practice, RL for robotics often struggles with complex environments because it relies on brittle, hand-engineered dense rewards or assumes unrealistic sampling budgets (e.g., relying on proximal heuristics while the true target is a sparse success outcome). I developed a novel RL framework that optimizes for target success outcomes without requiring (1) infinite sampling assumptions or (2) restrictive reward shaping.

Going Beyond Heuristics by Imposing Policy Improvement as a Constraint
Chi-Chang Lee*, Zhang-Wei Hong*, Pulkit Agrawal
Conference on Neural Information Processing Systems (NeurIPS), 2024
Paper | OpenReview | Video | Code

Maximizing Velocity by Minimizing Energy
Srinath Mahankali*, Chi-Chang Lee*, Gabriel B. Margolis, Zhang-Wei Hong, Pulkit Agrawal
International Conference on Robotics and Automation (ICRA), 2024
Paper | Website | Code


  Publications in Machine Learning for Audio Modalities

Machine Learning for Audio Modalities - My previous research mainly focused on “normalizing” speech from diverse acoustic conditions for downstream tasks such as Speech-to-Text and Speaker Identification. My related publications cover two main directions: (1) Leveraging multiple label modalities for auxiliary learning and data reuse, by combining synthetic and real-world audio, for example using pairs of noisy and clean speech (synthetic) and pairs of noisy speech and text labels (real-world) to improve robustness. (2) Fast adaptation and continual learning for acoustic normalization in order to mitigate out-of-domain degradation. Given the complexity of speech and acoustic environments, it is unrealistic to assume that audio models will generalize sufficiently on their own, so my work focuses on how to automatically acquire informative data and rapidly recalibrate these models.


D4AM: A General Denoising Framework for Downstream Acoustic Models
Chi-Chang Lee, Yu Tsao, Hsin-Min Wang, Chu-Song Chen
International Conference on Learning Representations (ICLR), 2023
Paper | Code

LC4SV: A Denoising Framework Learning to Compensate for Unseen Speaker Verification Models
Chi-Chang Lee, Hong-Wei Chen, Chu-Song Chen, Hsin-Min Wang, Tsung-Te Liu, Yu Tsao
IEEE Automatic Speech Recognition and Understanding Workshop (ASRU), 2023
Paper | Code

NASTAR: Noise Adaptive Speech Enhancement with Target-Conditional Resampling
Chi-Chang Lee, Cheng-Hung Hu, Yu-Chen Lin, Chu-Song Chen, Hsin-Min Wang, Yu Tsao
INTERSPEECH, 2022
Paper | Website | Code

SERIL: Noise adaptive speech enhancement using regularization-based incremental learning
Chi-Chang Lee, Yu-Chen Lin, Hsuan-Tien Lin, Hsin-Min Wang, Yu Tsao
INTERSPEECH, 2020
Paper | Code


  Teaching

Teaching Assistant, Machine Learning, National Taiwan University, Taiwan 2021 Fall

Teaching Assistant, Time Frequency Analysis and Wavelet Transforms, National Taiwan University, Taiwan 2018 Fall


  Honor

Second Place, IC/CAD Contest 2019



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