SPS SLTC/AASP Webinar: Ambisonics Recording and Encoding – from Spherical Arrays to Wearables
Date: 18-September-2025
Time: 08:00 AM ET (New York Time)
Presenter: Dr. Boaz Rafaely
About this topic:
Ambisonics offers a signal-independent and mathematically rigorous framework for representing spatial audio. Widely adopted in industry and deeply studied in academia, Ambisonics models the sound field around a listener’s head using spherical harmonics. This makes it particularly well suited for headphone-based applications such as music playback, virtual reality (VR), and augmented reality (AR). This webinar provides an overview of Ambisonics recording and encoding. It begins with the theoretical foundations of Ambisonics and its relation to the physical sound field, followed by practical encoding using spherical microphone arrays. The presenter then explores the challenges of capturing Ambisonics with arrays based on arbitrarily arranged microphones, such as those integrated into wearable devices like AR glasses, where spatial constraints demand novel solutions. Recent signal-independent approaches, such as Ambisonics Signal Matching (ASM), and signal-dependent techniques, including parametric encoding, are reviewed. Additionally, he will examine perceptually motivated encoding applied to head-related transfer functions (HRTFs), which enhances the quality of binaural reproduction. Finally, the webinar discusses emerging applications of AI in Ambisonics encoding and processing, highlighting its potential to overcome existing limitations and shape future research directions.
About the presenter:
Boaz Rafaely (SM’01) received the B.Sc. degree (cum laude) in electrical engineering from Ben-Gurion University, Beer-Sheva, Israel, in 1986; the M.Sc. degree in biomedical engineering from Tel-Aviv University, Israel, in 1994; and the Ph.D. degree from the Institute of Sound and Vibration Research (ISVR), Southampton University, U.K., in 1997.
He is currently heading the acoustics laboratory, investigating methods for audio signal processing and spatial audio at Ben-Gurion University where he joined the Department of Electrical and Computer Engineering as a Senior Lecturer in 2003, and was appointed Associate Professor in 2010, and Professor in 2013. At the ISVR, he was appointed Lecturer in 1997 and Senior Lecturer in 2001, working on active control of sound and acoustic signal processing. In 2002, he spent six months as a Visiting Scientist at the Sensory Communication Group, Research Laboratory of Electronics, Massachusetts Institute of Technology (MIT), Cambridge, investigating speech enhancement for hearing aids.
Dr. Rafaely served as an associate editor for IEEE Transactions on Audio, Speech and Language Processing from 2010-2014. and during 2013-2018 as a member of the IEEE Audio and Acoustic Signal Processing Technical Committee. He also served as an associate editor for IEEE Signal Processing Letters during 2015-2019, IET Signal Processing during 2016-2019, and currently for Acta Acustica. During 2013-2016 he has served as the chair of the Israeli Acoustical Association, and during 2016-2022 as the chair of the Technical Committee on Audio Signal Processing in the European Acoustical Association. He has served as the head of the School of Electrical and Computer Engineering at Ben-Gurion university between 2021-2024. Prof. Rafaely was awarded the British Council’s Clore Foundation Scholarship.
