(1) An umbrella term for surround sound systems that add a height channel. Also called "virtual surround sound" and "Immersive Sound," sound cards may use signal processing to simulate a 3D audio experience in headphones. See
OpenAL and
Auro-3D.
(2) (3D Audio) An MPEG-H standard for surround sound recording and playback. 3D Audio supports a mix of channel-based audio, object-based audio and Higher Order Ambisonics (HOA) with up to 64 speaker channels. See
surround sound and
MPEG-H.