Refers to Dolby Laboratories, which conducts R&D on sound recording and reproduction. It doesn't have audio products of its own; companies license Dolby technology to use it, along with the label, in their equipment. Dolby Digital uses a 5.1speaker system to create surround sound effects, and is commonly seen in consumer-grade speaker sets and sound cards. This technology is also called AC3, and is used in DVD video to deliver surround sound.