Audio format
Encyclopedia
An audio format is a medium for storing sound
Sound
Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...

 and music
Music
Music is an art form whose medium is sound and silence. Its common elements are pitch , rhythm , dynamics, and the sonic qualities of timbre and texture...

. The term is applied to both the physical recording media and the recording formats of the audio content
Audio frequency
An audio frequency or audible frequency is characterized as a periodic vibration whose frequency is audible to the average human...

 – in computer science
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...

 it is often limited to the audio file format
Audio file format
An audio file format is a file format for storing digital audio data on a computer system. This data can be stored uncompressed, or compressed to reduce the file size. It can be a raw bitstream, but it is usually a container format or an audio data format with defined storage layer.-Types of...

, but its wider use usually refers to the physical method used to store the data.

Music is recorded and distributed using a variety of audio formats, some of which store additional information.

Timeline of audio format developments

Year Media formats Recording formats
1877 Phonograph cylinder
Phonograph cylinder
Phonograph cylinders were the earliest commercial medium for recording and reproducing sound. Commonly known simply as "records" in their era of greatest popularity , these cylinder shaped objects had an audio recording engraved on the outside surface which could be reproduced when the cylinder was...

Mechanical analog; "hill-and-dale" grooves, vertical stylus motion
1883 Music roll
Piano roll
A piano roll is a music storage medium used to operate a player piano, piano player or reproducing piano. A piano roll is a continuous roll of paper with perforations punched into it. The peforations represent note control data...

Mechanical digital (automated musical instruments)
1895 Gramophone record
Gramophone record
A gramophone record, commonly known as a phonograph record , vinyl record , or colloquially, a record, is an analog sound storage medium consisting of a flat disc with an inscribed, modulated spiral groove...

Mechanical analog; lateral grooves, horizontal stylus motion
1898 Wire recording
Wire recording
Wire recording is a type of analog audio storage in which a magnetic recording is made on thin steel or stainless steel wire.The wire is pulled rapidly across a recording head which magnetizes each point along the wire in accordance with the intensity and polarity of the electrical audio signal...

Analog; magnetization; no "bias"
Tape bias
Tape bias is the term for two phenomena, DC bias and AC bias, that improve the fidelity of analogue magnetic tape sound recordings. DC bias is the addition of a direct current to the audio signal that is being recorded. AC bias is the addition of an inaudible high-frequency signal to the audio...

1925 Electrical cut record Mechanical analog; electrically cut from amplified microphone signal, lateral grooves, horizontal stylus motion, discs at 7", 10", 12", most at 78 rpm
1930s Reel-to-Reel, Magnetic Tape Analog; magnetization; "bias" dramatically increases linearity/fidelity, tape speed at 30 ips, later 15 ips with NAB equalization; refined speeds: 7½ ips, 3¾ ips, 1⅞ ips
Electrical transcriptions Mechanical analog; electrically cut from amplified microphone signal, high fidelity
High fidelity
High fidelity—or hi-fi—reproduction is a term used by home stereo listeners and home audio enthusiasts to refer to high-quality reproduction of sound or images, to distinguish it from the poorer quality sound produced by inexpensive audio equipment...

 sound, lateral or vertical grooves, horizontal or vertical stylus motion, most discs 16" at 33⅓ rpm
1948 Vinyl Record Analog, with preemphasis and other equalization techniques (LP, RIAA); lateral grooves, horizontal stylus motion; discs at 7" (most 45 rpm), 10" and 12" (most 33⅓ rpm)
1957 Stereophonic Vinyl Record Analog, with preemphasis and other equalization techniques. Combination lateral/vertical stylus motion with each channel encoded 45 degrees to the vertical.
1962 4-Track (Stereo-Pak) Analog, 1/4 in tape, 3¾ in/s, endless loop cartridge.
1963 Compact Cassette
Compact Cassette
The Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a magnetic tape sound recording format. It was designed originally for dictation, but improvements in fidelity led the Compact Cassette to supplant the Stereo 8-track cartridge and reel-to-reel...

Analog, with bias, preemphasis, 0.15 inches (3.8 mm) tape, 1⅞ in/s. 1970: introduced Dolby noise reduction.
1965 8-Track (Stereo-8) Analog, ¼ inch wide tape, 3¾ in/s, endless loop cartridge.
1969 Microcassette
Microcassette
A Microcassette is an audio storage medium introduced by Olympus in 1969. It uses the same width of magnetic tape as the Compact Cassette but in a much smaller container. By using thinner tape and half or a quarter the tape speed, microcassettes can offer comparable recording time to the compact...

Analog, ⅛ inch wide tape, used generally for notetaking, mostly mono, some stereo. 2.4 cm/s or 1.2 cm/s.
Minicassette
Minicassette
The Mini-Cassette, often written minicassette, is a tape cassette format introduced by Philips in 1967. It is used primarily in dictation machines and was also employed as a data storage for the Philips P2000 home computer...

Analog, ⅛ inch wide tape, used generally for notetaking, 1.2 cm/s
1970 Quadraphonic
Quadraphonic
Quadraphonic sound – the most widely used early term for what is now called 4.0 surround sound – uses four channels in which speakers are positioned at the four corners of the listening space, reproducing signals that are independent of one another...

 8-Track (Quad-8) (Q8)
Analog, ¼ inch wide tape, 3¾ in/s, 4 Channel Stereo, endless loop cartridge.
1971 Quadraphonic
Quadraphonic
Quadraphonic sound – the most widely used early term for what is now called 4.0 surround sound – uses four channels in which speakers are positioned at the four corners of the listening space, reproducing signals that are independent of one another...

 Vinyl Record (CD-4) (SQ Matrix)
Analog.
1975 Betamax Digital Audio Dolby Stereo
Dolby Stereo
Dolby Stereo, is the trade mark that Dolby Laboratories used for the various analogue stereo cinema sound formats that they produced.Two basic systems used this name. The first was the 'Dolby SVA' system used with optical soundtracks on 35mm film...

 cinema surround sound
1976 Elcaset
Elcaset
Elcaset was a short-lived audio format created by Sony in 1976, building on an idea introduced 20 years earlier in the RCA tape cartridge.In 1976, it was widely felt that the compact cassette was never likely to be capable of the same levels of performance that was available from reel-to-reel...

Analog.
1978 Laserdisc
Laserdisc
LaserDisc was a home video format and the first commercial optical disc storage medium. Initially licensed, sold, and marketed as MCA DiscoVision in North America in 1978, the technology was previously referred to interally as Optical Videodisc System, Reflective Optical Videodisc, Laser Optical...

Digital.
1982 Compact Disc
Compact Disc
The Compact Disc is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but later expanded to encompass data storage , write-once audio and data storage , rewritable media , Video Compact Discs , Super Video Compact Discs ,...

 (CD-DA)
Digital. PCM
1985 Audio Interchange File Format
AIFF
Audio Interchange File Format is an audio file format standard used for storing sound data for personal computers and other electronic audio devices...

 (AIFF)
1985 Sound Designer (by Digidesign
Digidesign
Avid Audio is an American digital audio technology company. It was founded in 1984 by Peter Gotcher and Evan Brooks. The company began as a project to raise money for the founders' band, selling EPROM chips for drum machines. It is a subsidiary of Avid Technology, and during 2010 the Digidesign...

)
1986 High Definition Compatible Digital
High Definition Compatible Digital
High Definition Compatible Digital, or HDCD is a patented encode-decode process, now owned by Microsoft, that improves the audio quality of standard Redbook audio CDs, while retaining backward compatibility with existing Compact disc players....

 (HDCD)
Digital. Redbook compatible physical CD containing 20–24 bit information.
1987 Digital Audio Tape
Digital Audio Tape
Digital Audio Tape is a signal recording and playback medium developed by Sony and introduced in 1987. In appearance it is similar to a compact audio cassette, using 4 mm magnetic tape enclosed in a protective shell, but is roughly half the size at 73 mm × 54 mm × 10.5 mm. As...

 (DAT)
Digital.
1991 MiniDisc
MiniDisc
The disc is permanently housed in a cartridge with a sliding door, similar to the casing of a 3.5" floppy disk. This shutter is opened automatically by a mechanism upon insertion. The audio discs can either be recordable or premastered. Recordable MiniDiscs use a magneto-optical system to record...

 (MD)
Digital. Adaptive Transform Acoustic Coding (ATRAC)
1992 Digital Compact Cassette
Digital Compact Cassette
Digital Compact Cassette was a magnetic tape sound recording format introduced by Philips and Matsushita in late 1992 and pitched as a successor to the standard analog cassette. It was also a direct competitor to Sony's MiniDisc but neither format toppled the then ubiquitous analog cassette...

 (DCC)
Digital.
WAVEform
WAV
Waveform Audio File Format , is a Microsoft and IBM audio file format standard for storing an audio bitstream on PCs...

 (WAV)
Dolby Digital
Dolby Digital
Dolby Digital is the name for audio compression technologies developed by Dolby Laboratories. It was originally called Dolby Stereo Digital until 1994. Except for Dolby TrueHD, the audio compression is lossy. The first use of Dolby Digital was to provide digital sound in cinemas from 35mm film prints...

 surround cinema sound
1993 Digital Theatre System (DTS)
Sony Dynamic Digital Sound (SDDS)
MPEG-1 Audio Layer III
MP3
MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3, is a patented digital audio encoding format using a form of lossy data compression...

1997 DVD
DVD
A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....

Dolby Digital
Dolby Digital
Dolby Digital is the name for audio compression technologies developed by Dolby Laboratories. It was originally called Dolby Stereo Digital until 1994. Except for Dolby TrueHD, the audio compression is lossy. The first use of Dolby Digital was to provide digital sound in cinemas from 35mm film prints...

DTS-CD DTS Audio
1999 DVD-Audio
DVD-Audio
DVD-Audio is a digital format for delivering high-fidelity audio content on a DVD. DVD-Audio is not intended to be a video delivery format and is not the same as video DVDs containing concert films or music videos....

Digital.
Super Audio CD
Super Audio CD
Super Audio CD is a high-resolution, read-only optical disc for audio storage. Sony and Philips Electronics jointly developed the technology, and publicized it in 1999. It is designated as the Scarlet Book standard. Sony and Philips previously collaborated to define the Compact Disc standard...

 (SACD)
Direct Stream Digital
Direct Stream Digital
Direct-Stream Digital is the trademark name used by Sony and Philips for their system of recreating audible signals which uses pulse-density modulation encoding, a technology to store audio signals on digital storage media which is used for the Super Audio CD .The signal is stored as delta-sigma...

Windows Media Audio
Windows Media Audio
Windows Media Audio is an audio data compression technology developed by Microsoft. The name can be used to refer to its audio file format or its audio codecs. It is a proprietary technology that forms part of the Windows Media framework. WMA consists of four distinct codecs...

 (WMA)
The True Audio Lossless Codec
TTA (codec)
True Audio is a free software, real-time lossless audio codec, based on adaptive prognostic filters.Also, .tta is the generic extension to filenames of audio files created by True Audio codec.- Codec overview :...

 (TTA)
2000 Free Lossless Audio Codec
FLAC
FLAC is a codec which allows digital audio to be losslessly compressed such that file size is reduced without any information being lost...

 (FLAC)
2001 Advanced audio coding
Advanced Audio Coding
Advanced Audio Coding is a standardized, lossy compression and encoding scheme for digital audio. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates....

 (AAC)
2002 Ogg Vorbis
2003 DualDisc
DualDisc
DualDisc was a type of double-sided optical disc product developed by a group of record companies including EMI Music, Universal Music Group, Sony/BMG Music Entertainment, Warner Music Group, and 5.1 Entertainment Group and later under the aegis of the Recording Industry Association of America...

Digital.
2004 Apple Lossless
Apple Lossless
Apple Lossless Apple Lossless Apple Lossless (also known as ALAC (Apple Lossless Audio Codec), or ALE (Apple Lossless Encoder) is an audio codec developed by Apple Inc. for lossless data compression of digital music. After initially being proprietary for many years, in late 2011 Apple open sourced...

 (ALE or ALAC)
2005 HD DVD
HD DVD
HD DVD is a discontinued high-density optical disc format for storing data and high-definition video.Supported principally by Toshiba, HD DVD was envisioned to be the successor to the standard DVD format...

Dolby TrueHD
Dolby TrueHD
Dolby TrueHD is an advanced lossless multi-channel audio codec developed by Dolby Laboratories which is intended primarily for high-definition home-entertainment equipment such as Blu-ray Disc and HD DVD. It is the successor to the AC-3 Dolby Digital surround sound codec which was used as the...

, DTS-HD Master Audio
DTS-HD Master Audio
DTS-HD Master Audio is a lossless audio codec created by Digital Theater System. It was previously known as DTS++. It is an extension of DTS which, when played back on devices which do not support the Master Audio or High Resolution extension, degrades to a "core" track which is lossy. DTS-HD...

OggPCM
OggPCM
OggPCM is a data format which is used to encapsulate PCM audio data inside the Ogg container format. It is developed by Xiph.Org Foundation. Like WAV, and unlike MP3 or Vorbis, it deals with uncompressed digital sound, making the format lossless. Like Vorbis, it could be used in separation from the...

2006 Blu-ray Disc
Blu-ray Disc
Blu-ray Disc is an optical disc storage medium designed to supersede the DVD format. The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and CDs. Blu-ray Discs contain 25 GB per layer, with dual layer discs being the norm for feature-length video discs...

Dolby TrueHD
Dolby TrueHD
Dolby TrueHD is an advanced lossless multi-channel audio codec developed by Dolby Laboratories which is intended primarily for high-definition home-entertainment equipment such as Blu-ray Disc and HD DVD. It is the successor to the AC-3 Dolby Digital surround sound codec which was used as the...

, DTS-HD Master Audio
DTS-HD Master Audio
DTS-HD Master Audio is a lossless audio codec created by Digital Theater System. It was previously known as DTS++. It is an extension of DTS which, when played back on devices which do not support the Master Audio or High Resolution extension, degrades to a "core" track which is lossy. DTS-HD...

2008 slotMusic
SlotMusic
slotMusic is a type of microSD memory card developed by SanDisk preloaded with music in MP3 format. They were first available at Wal-Mart and Best Buy stores in the United States in October 2008. The current selection of songs comes from Universal Music Group, Sony BMG, Warner Music Group and EMI...

320kb/s MP3 on microSD or microSDHC


NEW CD
Blu-spec CD
Blu-spec CD
Blu-spec CD describes an Audio CD manufactured by a proprietary process introduced by Sony Music Entertainment Japan in late 2008. Its name derives from the similar manufacturing process to that used to create Blu-ray Discs. Instead of a traditional infra-red laser, a blue laser is used for...


External links

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