An audio object is the basic unit of object-based audio: a single sound — a voice, a passing car, a helicopter — bundled with metadata that describes its position (x, y, z), size, and level over time. Instead of being mixed into a fixed channel, the object stays separate until playback, when a renderer places it on the listener's actual speakers or headphones according to that metadata. Keeping sounds as discrete objects is what gives Dolby Atmos and MPEG-H their flexibility: objects can be positioned with height and precision, moved dynamically, individually adjusted (a dialogue object boosted for clarity), or swapped (a different language object). A typical Atmos mix combines a channel bed with up to a hundred or so such objects.
The book · Volume 5 of 7
Audio for Video: A Complete Guide to Sound in Video Products: From Jitter Buffers and Lip Sync to Atmos, Quality Metrics, and Neural Codecs
An audio object keeps a sound separate from the mix until playback, which is what lets one master play correctly on headphones, soundbars and cinemas. Volume 5 covers the audio object in detail within spatial audio: object-based versus channel-based sound, Dolby Atmos, binaural rendering and keeping objects in sync with video. Written by Nikolay Sapunov, CEO at Fora Soft.
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