Professor Chi’s research has focused on machine perception, auditory modelling, speech signal processing, digital communications, and neural computation, with particular emphasis on integrating auditory physiology, artificial neural networks, and speaker-recognition technologies. In the early 1970s, he led the development of China’s first spread-spectrum CDMA satellite communication system for Project 331, and in 1976 directed the research group that completed China’s first operational optical-fibre communication system. From 1987 to 1997, he led major research projects on artificial-neural-network-based speaker recognition and auditory modelling supported by the National Natural Science Foundation of China and the National Climbing Programme. This work contributed to the development of computational approaches to speech recognition and auditory information processing and was recognised with the First Prize of the Ministry of Education Science and Technology Progress Award in 1999. He has authored more than one hundred peer-reviewed publications and monographs including Digital Speech Signal Processing and has supervised and trained generations of scientists and engineers. Through sustained leadership of national key laboratories and major research programmes, Professor Chi has contributed to the development of signal-processing methods and intelligent information technologies, connecting fundamental research in neural computation and auditory processing with applications in telecommunications, speech technologies, and human–machine interaction.