Dolby Atmos is a surround sound technology developed by Dolby Laboratories. It expands on existing surround sound systems by adding height channels, interpreted as three-dimensional objects with neither horizontal nor vertical limitations.[1][2] Following the release of Atmos for the cinema market, a variety of consumer technologies have been released under the Atmos brand. The initial cinema Atmos systems used in-ceiling speakers, then upward-firing speakers (e.g. for soundbars) were introduced as an alternative for consumer products.[3] Atmos is also used on some devices that do not have a height channel, such as headphones, televisions, mobile phones, and tablets.[4][5][6]