Dolby Surround 7.1 is a surround 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 rear surround channels to 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. From Wikipedia
