A Seven-Year Corpus of Higher-Order Ambisonics Recordings

Higher-Order Ambisonics (HOA) recording corpus comprising 23 sessions captured April 2019 – January 2026 using spherical microphone arrays. Contains 74 rendered B-format files (~155 GB, 16+ hours) spanning concert halls, churches, studios, outdoor locations, and VR film production sets. Musical content includes solo piano, choir, chamber music, folk/ethno music, ambient soundscapes, and VR film production audio.
The corpus was captured primarily with the Zylia ZM-1 (19 MEMS capsules, 3rd-order Ambisonics), with comparative recordings from the Harpex Spcmic (5th-order) and Saramonic SR-VRMIC (1st-order). All files are processed to B-format using ACN channel ordering and SN3D normalization. Sessions are peak-normalized to −0.5 dBTP, preserving relative loudness relationships between pieces within each session. Sampling rates are 48 kHz (Zylia ZM-1) and 48–96 kHz (Harpex Spcmic) at 24–32-bit depth.
Recording venues are concentrated in the Gdańsk-Sopot-Gdynia metropolitan area (Poland), including the Aula of Gdańsk University of Technology (RT60 = 1.97 s), Oliwa Cathedral and Holy Trinity Church, the Polish Baltic Philharmonic, and Stanisław Moniuszko Academy of Music. Outdoor locations include the Baltic Sea pier in Sopot and Piechcin Quarry (~200 km south of Gdańsk).
The corpus supports research in spatial audio quality assessment, machine learning for acoustic scene classification and source separation, room acoustic simulation validation, and immersive audio production education. A dedicated co-located microphone comparison session enables analysis of spatial energy distribution across Ambisonics orders, revealing significant differences between consumer-grade MEMS arrays and professional systems.
Note on excluded content: Two sessions are not included in this corpus – a 2023 choir/cabaret concert (restricted due to ZAiKS copyright on the performed repertoire) and a 2023 piano/tenor recording (not cleared by the performers). One individual file from the 2022-06-27 piano session (Paweł Mykietyn – Prelude) is similarly excluded due to composer licensing restrictions. These recordings are not available for distribution.