When we look at where television audio standards stand today, it’s hard to reconcile the initial mono sound broadcasts from television’s infancy to where it has evolved with the capabilities of the next generation of broadcast standards, part of ATSC 3.0. This progression of television audio from mono led first to stereo, then a second audio language program (SAP), to ATSC 1.0 digital with the availability of Dolby AC3 Surround Sound—each step advancing audio technology on a steady progression towards making sound more realistic and engaging.

Source: Next-Gen TV Promises Immersive, Personalized Audio | TvTechnology