Ambisonics

A full-sphere surround sound technique that captures and reproduces audio from all directions — including above and below the listener — using a spherical harmonic representation of the sound field. Originally developed by Michael Gerzon in the 1970s, ambisonics differs from channel-based surround sound in that it encodes a complete sound field independent of any specific speaker layout and can be decoded to any reproduction system, from headphones to multi-speaker arrays. First-order ambisonics uses four channels (the B-format), while higher-order ambisonics provides greater spatial resolution. In accessibility, ambisonics is particularly relevant for virtual reality and 360-degree media, where it enables sound sources to remain correctly positioned as the user turns their head, supporting spatial audio descriptions and non-visual navigation in immersive environments.