Object-Based Audio
Definition
An approach to audio mixing in which individual sounds are treated as independent objects with metadata describing their position, size, and movement in three-dimensional space, rather than being assigned to fixed speaker channels.
In Simple Terms
Instead of assigning sounds to fixed speakers, each sound gets a 3D position—'this guitar is here, that drum is over there.' The playback system figures out how to recreate those positions with whatever speakers are available.
In Practice
In a Dolby Atmos mix, a helicopter is placed as an audio object moving from front left, overhead, to behind the listener — the Atmos renderer interprets this path for any speaker configuration.
Dolby Atmos Context
Object-based audio is the core innovation that makes Dolby Atmos scalable. The same mix file renders for a stereo soundbar, a 5.1.2 home theater, or a 9.1.6 cinema by interpreting the object metadata for the available speakers.