Editing Ambisonics (section)

{{Short description|Full-sphere surround sound format}}
{{Distinguish|Ambiophonics}}
{{merge from|Ambisonic decoding|date=January 2025|discuss=Talk:Ambisonics#Merge_from_Ambisonic_decoding}}
{{Use dmy dates|date=July 2020}}
[[Image:AmbisonicLogo.svg|thumb|200px|right|Ambisonics former trademark]]

'''Ambisonics''' is a ''full-sphere'' [[surround sound]] format: in addition to the horizontal plane, it covers sound sources above and below the listener.<ref>Michael A. Gerzon, ''Periphony: With-Height Sound Reproduction''. Journal of the Audio Engineering Society, 1973, 21(1):2–10.</ref><ref>Franz Zotter and Matthias Frank, [https://doi.org/10.1007/978-3-030-17207-7 ''Ambisonics: A Practical 3D Audio Theory for Recording, Studio Production, Sound Reinforcement, and Virtual Reality'']. SpringerOpen, 2019.</ref>

Unlike some other multichannel surround formats, its transmission channels do not carry speaker signals. Instead, they contain a speaker-independent representation of a sound field called ''B-format'', which is then ''decoded'' to the listener's speaker setup. This extra step allows the producer to think in terms of source directions rather than loudspeaker positions, and offers the listener a considerable degree of flexibility as to the layout and number of speakers used for playback.

Ambisonics was developed in the UK in the 1970s under the auspices of the British [[National Research Development Corporation]].

Despite its solid technical foundation and many advantages, Ambisonics had not until recently{{when|date=March 2023}} been a commercial success, and survived only in niche applications and among recording enthusiasts.

With the widespread availability of powerful digital signal processing (as opposed to the expensive and error-prone analog circuitry that had to be used during its early years) and the successful market introduction of home theatre surround sound systems since the 1990s, interest in Ambisonics among recording engineers, sound designers, composers, media companies, broadcasters and researchers has returned and continues to increase.

In particular, it has proved an effective way to present spatial audio in Virtual Reality applications (e.g. YouTube 360 Video), as the B-Format scene can be rotated to match the user's head orientation, and then be decoded as binaural stereo.