Dolby Surround 7.1 (sometimes called Dolby 7.1 surround sound) is a sound system by Dolby Laboratories which delivers theatrical 7.1 surround sound to movie-goers.
It is the most recent addition to a family of audio compression technologies developed by Dolby known as Dolby Digital.
It adds two new channels to current Dolby Digital 5.1.
The first film to feature Dolby Surround 7.1 was 2010's Toy Story 3 by Walt Disney Pictures and Pixar.
[1][2] Dolby Surround 7.1 was used to mix in movies and display in movie theaters, from 2010 to 2014, until Dolby Atmos superseded it in 2018.