Dolby Atmos

Dolby Atmos is a surround sound technology developed by Dolby Laboratories. It expands on existing surround sound systems by adding height channels as well as free-moving sound objects, 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]

History

The first Dolby Atmos installation was in the El Capitan Theatre in Los Angeles, for the premiere of Brave in June 2012.[7] Throughout 2012, it saw a limited release of about 25 installations worldwide, with an increase to more than 300 locations in 2013.[8] As of April 2023, there were over 7,800 cinema screens, across 105 countries, which supported or were committed to support Dolby Atmos.[9] Dolby Atmos has also been adapted to a home theater format and is the audio component of Dolby Cinema.[10] Electronic devices from 2016 onwards, along with smartphones starting in 2017, have included support for Dolby Atmos recording and mixing capabilities. The full set of technical specifications for Dolby Digital Plus with Dolby Atmos are standardized and published in ETSI TS 103 420.[11]

Technology

Dolby Atmos technology allows the storage and distribution of 128 audio tracks with metadata describing sound properties such as position and volume (and their variation over time). The audio mix is rendered specifically for the theater's setup using the loudspeakers available. Each audio track can be assigned to an audio channel, the conventional format for distribution, or to an audio "object". Dolby Atmos in theaters has a 9.1 (commonly referred to as 7.1.2) channel-based "bed" channels for ambience stems or center dialogue, leaving 118 tracks for objects.[14] Atmos for home in film, television, and music uses a technique called "spatial coding" to reduce the audio to up to a maximum of 16 concurrent "elements" or audio location clusters, that adapt to the content dynamically.[15] In Atmos games, ISF (Intermediate Spatial format) is used, which supports 32 total active objects (using a 7.1.4 bed, 20 additional dynamic objects can be active).[16] Each object specifies its apparent source location in the theater as a set of three-dimensional rectangular coordinates relative to the defined audio channel locations and theater boundaries.[17]

Consumer implementations

Compatibility

Dolby Atmos is adaptable and can be played back on various speaker setups. As well, many audio products provide additional support for Dolby Atmos.[63]

The technology has been licensed to other brands by Dolby. Since its launch, the Dolby Atmos format has been used by/affiliated with several companies in consumer technology as well as major film productions. This has added to the overall availability of content for Dolby Atmos users.[2]

See also

• A3D, a similar, HRTF-based 3D surround sound system
• Ambisonics, a similar spatial sound encoding technique. Nowadays used for some games and VR Audio
• Auro-3D, a similar, completely channel-based 3D surround sound system
• Eclipsa Audio, open source immersive audio format by Google and Samsung
• DTS:X, a competing fully object-based system
• MPEG-H 3D Audio
• Sound Blaster X-Fi, a competing surround sound "audio holography" system for headphones tuned to ear shape.
• EAX, Creative, real-time multi-object spatial audio rendering implementation
• Nokia OZO, a similar spatial sound technique, specifically used for a 360 audio experience in communication.

External links