What defines object-based audio compared to older channel-based methods?

Audio sources are encoded with positional metadata for dynamic placement.

Object-based audio represents a major conceptual leap away from earlier channel-based methods of spatialization. Channel-based techniques were intrinsically linked and fixed to a specific, predetermined speaker layout, meaning the mix was designed for one setup only. In contrast, object-based audio functions by encoding individual audio sources with associated positional metadata. This metadata dictates where the sound object should exist in three-dimensional space. A renderer then interprets this data dynamically, allowing the sound to be placed precisely according to the metadata irrespective of the final playback device configuration, offering far greater flexibility and realistic spatial placement, as seen in systems like Dolby Atmos.