Dolby Atmos is Dolby's object-based immersive audio system, which adds height and precise placement to surround sound. Instead of mixing only to fixed channels, it combines a channel 'bed' (commonly 7.1.2) with up to 118 dynamic audio objects, each tagged with positional metadata, and a renderer places those objects on whatever speakers — or virtualized headphones — the listener actually has. Delivery varies by context: Dolby TrueHD with Atmos on Blu-ray, E-AC-3 with Joint Object Coding (JOC) for most streaming, AC-4 IMS for broadcast, and binaural rendering on headphones and earbuds, increasingly with head tracking. Atmos is how 'immersive audio' reaches mainstream living rooms, cinemas, and Apple Music.
