Opening
Keynote Speaker
Keynote 1 - Ambisonics Signal Processing: From Spherical Array Theory to Machine Learning Challenges
Prof. Boaz Rafaely / Ben-Gurion University of the Negev
2026-09-08 | 08:30-09:30 (Europe/Rome)
Ambisonics is a versatile framework for spatial audio capture, encoding, and reproduction, with growing adoption in industry as the standard format for immersive spatial audio. Ambisonics is based on the spherical harmonics representation of sound fields, with its signal processing having evolved from classical spherical array theory to modern machine learning. This talk reviews Ambisonics encoding approaches as a means to generate Ambisonics signals from microphone recordings, first for spherical arrays, then for wearable arrays and arrays of unconstrained geometry using methods ranging from linear Ambisonics Signal Matching to neural network-based approaches that implicitly leverage information in the audio data. Neural network-based approaches, once incorporated into spatial audio applications, require loss functions that reflect auditory spatial perception, a topic of growing interest that also opens new challenges. These perceptual loss functions are particularly relevant to recent work on Ambisonics upscaling - moving beyond first-order to higher-order representations. Beyond upscaling, Ambisonics further extends to speech enhancement, both for improving spatial audio quality and, more broadly, for enabling array-agnostic processing through its modular, geometry-independent structure. Together, these topics illustrate the growing role of Ambisonics as a unifying representation in spatial audio and point to promising directions for future research.
Bio
Boaz Rafaely is a Professor at Ben-Gurion University of the Negev in Israel, where he leads the Acoustics Laboratory, conducting research in spatial audio signal processing. He has published over 200 papers in journals and conferences, and is the author of the book Fundamentals of Spherical Array Processing. Prof. Rafaely has previously served as Head of the School of Electrical and Computer Engineering at BGU, Chair of the Israeli Acoustical Association, and Chair of the Technical Committee on Audio Signal Processing of the European Acoustical Association. He has also been an associate editor for IEEE Transactions on Audio, Speech and Language Processing, IEEE Signal Processing Letters, and Acta Acustica. He is an IEEE fellow.