In digital recording, an

audio Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to: Sound * Audio signal, an electrical representation of sound *Audio frequency, a frequency in the audio spectrum * Digital audio, representation of sou ...

video signal Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) sy ...

is converted into a stream of

discrete number In mathematics and statistics, a quantitative variable may be continuous or discrete if they are typically obtained by ''measuring'' or ''counting'', respectively. If it can take on two particular real values such that it can also take on all ...

s representing the changes over time in

air pressure Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars ...

for audio, or chroma and luminance values for video. This number stream is saved to a storage device. To play back a digital recording, the numbers are retrieved and converted back into their original

analog Analog or analogue may refer to: Computing and electronics * Analog signal, in which information is encoded in a continuous variable ** Analog device, an apparatus that operates on analog signals *** Analog electronics, circuits which use analog ...

audio or video forms so that they can be heard or seen. In a properly matched

analog-to-digital converter In electronics, an analog-to-digital converter (ADC, A/D, or A-to-D) is a system that converts an analog signal, such as a sound picked up by a microphone or light entering a digital camera, into a digital signal. An ADC may also provide ...

(ADC) and

digital-to-analog converter In electronics, a digital-to-analog converter (DAC, D/A, D2A, or D-to-A) is a system that converts a digital signal into an analog signal. An analog-to-digital converter (ADC) performs the reverse function. There are several DAC archit ...

(DAC) pair the analog signal is accurately reconstructed per the constraints of the

Nyquist–Shannon sampling theorem The Nyquist–Shannon sampling theorem is a theorem in the field of signal processing which serves as a fundamental bridge between continuous-time signals and discrete-time signals. It establishes a sufficient condition for a sample rate that per ...

dependent on the

sampling rate In signal processing, sampling is the reduction of a continuous-time signal to a discrete-time signal. A common example is the conversion of a sound wave to a sequence of "samples". A sample is a value of the signal at a point in time and/or s ...

and quantization error dependent on the

or video bit depth. Because the signal is stored digitally, assuming proper error detection and correction, the recording is not degraded by copying, storage or interference.

Timeline

*October 3, 1938: British telephone engineer Alec Harley Reeves files at the

French Patent Office The National Industrial Property Institute (INPI, standing for ''Institut national de la propriété industrielle'' in French) is the national intellectual property office of France, in charge of patents, trademarks and industrial design rights. ...

the first patent describing the technique known today as

pulse-code modulation Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM Stream (comp ...

(PCM). On November 22, 1939, Reeves files also in the US. It was first proposed as a

telephony Telephony ( ) is the field of technology involving the development, application, and deployment of telecommunication services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is i ...

technology. *1943:

Bell Telephone Laboratories Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by mult ...

develops the first PCM-based digital scrambled speech transmission system,

SIGSALY SIGSALY (also known as the X System, Project X, Ciphony I, and the Green Hornet) was a secure speech system used in World War II for the highest-level Allied communications. It pioneered a number of digital communications concepts, including the ...

, in response to German interception of military telephone traffic during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

. The twelve transmission points were retired after the war. *June 1950:

Differential pulse-code modulation Differential pulse-code modulation (DPCM) is a signal encoder that uses the baseline of pulse-code modulation (PCM) but adds some functionalities based on the prediction of the samples of the signal. The input can be an analog signal or a digital ...

(DPCM) developed by

C. Chapin Cutler Cassius Chapin Cutler (December 16, 1914 – December 1, 2002) was an American electrical engineer at Bell Labs. His notable achievements include the invention of the corrugated waveguide and differential pulse-code modulation (DPCM). Biogr ...

at Bell Labs. *1957:

Max Mathews Max Vernon Mathews (November 13, 1926 in Columbus, Nebraska, USA – April 21, 2011 in San Francisco, CA, USA) was a pioneer of computer music. Biography Mathews studied electrical engineering at the California Institute of Technology and the Ma ...

of Bell develops the process to digitally record sound on a computer. *1967: The first

monaural Monaural or monophonic sound reproduction (often shortened to mono) is sound intended to be heard as if it were emanating from one position. This contrasts with stereophonic sound or ''stereo'', which uses two separate audio channels to reproduc ...

PCM encoder was developed by

NHK , also known as NHK, is a Japanese public broadcaster. NHK, which has always been known by this romanized initialism in Japanese, is a statutory corporation funded by viewers' payments of a television license fee. NHK operates two terrestr ...

's research facilities in Japan. The 30 kHz 12-bit device used a

compander In telecommunication and signal processing, companding (occasionally called compansion) is a method of mitigating the detrimental effects of a channel with limited dynamic range. The name is a portmanteau of the words compressing and expanding, ...

(similar to DBX Noise Reduction) to extend the dynamic range, and stored the signals on a

video tape recorder A video tape recorder (VTR) is a tape recorder designed to record and playback video and audio material from magnetic tape. The early VTRs were open-reel devices that record on individual reels of 2-inch-wide (5.08 cm) tape. They were u ...

. *1969: NHK expands the PCM encoder's capabilities to two-channel stereo and 32 kHz 13-bit resolution. *1969: The

charge-coupled device A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a ...

, the first image sensor used in digital imaging, invented by Willard S. Boyle and

George E. Smith George Elwood Smith (born May 10, 1930) is an American scientist, applied physicist, and co-inventor of the charge-coupled device (CCD). He was awarded a one-quarter share in the 2009 Nobel Prize in Physics for "the invention of an imaging semico ...

at Bell Labs, based on

MOS capacitor The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a type of field-effect transistor (FET), most commonly fabricated by the controlled oxidation of silicon. It has an insulated gate, the voltage of which d ...

technology. *1970: James Russell patents the first digital-to-optical recording and playback system, which would later lead to the

Compact Disc The compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then released in Oc ...

. *January 1971: Using NHK's experimental PCM recording system, Dr. Takeaki Anazawa, an engineer at Denon, records the world's first commercial digital recordings, ''The World Of Stomu Yamash'ta 1 & 2'' by Stomu Yamash'ta (January 11, 1971) and ''Something'' by Steve Marcus & Jiro Inagaki (January 25, 1971). Both had to be recorded live, without edits. Marcus is released first (in February 1972), making it the first released digital recording. On January 27 Yamash'ta records ''Metempsychosis'' in the Nippon Columbia studio, Tokyo, with percussion and a brass section. *1972: Using lessons learned from the NHK encoder, Denon unveils the first 8-channel PCM encoder, the DN-023R, which uses 47.25 kHz 13-bit PCM resolution and 4-head open reel broadcast

. The first recording with this new system is the

Smetana Quartet The Smetana Quartet ( cs, Smetanovo kvarteto) was a Czech string quartet that was in existence from 1945 to 1989. Personnel 1st violin * Václav Neumann (1920-1995), from 1943 to 1945 * Jaroslav Rybenský, from 1945 to 1947 * Jiří Novák (192 ...

performing Mozart's ''String Quartets K.458 and K.421'', recorded in Tokyo April 24–26 and released that October. At least six other Denon-recorded digital LP records are released in October, including jazz, classical and traditional Japanese music. *1973:

Adaptive differential pulse-code modulation Adaptive differential pulse-code modulation (ADPCM) is a variant of differential pulse-code modulation (DPCM) that varies the size of the quantization step, to allow further reduction of the required data bandwidth for a given signal-to-noise rati ...

(ADPCM) developed by P. Cummiskey,

Nikil Jayant Nikil S. Jayant (1945 -- ) is an Indian-American communications engineer. He was a prominent long-term researcher at Bell Laboratories and subsequently a professor at Georgia Institute of Technology. He received his Ph.D. in Electrical Communicatio ...

and

James L. Flanagan James Loton Flanagan (August 26, 1925 – August 25, 2015) was an American electrical engineer. He was Rutgers University's vice president for research until 2004. He was also director of Rutgers' Center for Advanced Information Processing and t ...

at Bell Labs. *December 2–3, 1974: The Paillard Chamber Orchestra records the first digital recording outside Japan, in

Paris Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. S ...

Notre Dame Cathedral Notre-Dame de Paris (; meaning "Our Lady of Paris"), referred to simply as Notre-Dame, is a medieval Catholic cathedral on the Île de la Cité (an island in the Seine River), in the 4th arrondissement of Paris. The cathedral, dedicated to the ...

, using Denon's DN-023R.

Bach Johann Sebastian Bach (28 July 1750) was a German composer and musician of the late Baroque period. He is known for his orchestral music such as the ''Brandenburg Concertos''; instrumental compositions such as the Cello Suites; keyboard wor ...

's "

The Musical Offering ''The Musical Offering'' (German: or ), Bach-Werke-Verzeichnis, BWV 1079, is a collection of keyboard canon (music), canons and fugues and other pieces of music by Johann Sebastian Bach, all based on a single musical Subject (music), theme given ...

" (BWV 1079) is released on LP May 1975. *December 12–19, 1974:

Helmuth Rilling Helmuth Rilling (born 29 May 1933) is a German choral conductor and an academic teacher. He is the founder of the Gächinger Kantorei (1954), the Bach-Collegium Stuttgart (1965), the Oregon Bach Festival (1970), the Internationale Bachakademie ...

records three

organ works inside the Gedächtniskirche,

Stuttgart Stuttgart (; Swabian: ; ) is the capital and largest city of the German state of Baden-Württemberg. It is located on the Neckar river in a fertile valley known as the ''Stuttgarter Kessel'' (Stuttgart Cauldron) and lies an hour from the ...

Germany using the DN-023R. *May 1975:

University of Utah The University of Utah (U of U, UofU, or simply The U) is a public research university in Salt Lake City, Utah. It is the flagship institution of the Utah System of Higher Education. The university was established in 1850 as the University of De ...

professor

Thomas Stockham Thomas Greenway Stockham (December 22, 1933 – January 6, 2004) was an American scientist who developed one of the first practical digital audio recording systems, and pioneered techniques for digital audio recording and processing. He also l ...

develops a PCM digital audio recorder of his own design, using computer tape drives as the storage system. He founds the company

Soundstream Soundstream Inc. was the first United States audiophile digital audio recording company, providing commercial services for recording and computer-based editing.Robert Easton, ''Soundstream, the first Digital Studio'', Recording Engineer/Producer, ...

to offer it commercially. Between 1977 and 1980 a total of eighteen 4-channel 50 kHz 16-bit units were manufactured, of which seven were sold at about US$150,000 () each. Over 200 recordings were made on his equipment, almost half of all digital classical recordings made in the 1970s. *1976: The prototype

37.5 kHz, 16-bit, 2-channel recorder is used to record the

Santa Fe Opera Santa Fe Opera (SFO) is an American opera company, located north of Santa Fe, New Mexico. After creating the ''Opera Association of New Mexico'' in 1956, its founding director, John Crosby, oversaw the building of the first opera house on a newl ...

performing

Virgil Thomson Virgil Thomson (November 25, 1896 – September 30, 1989) was an American composer and critic. He was instrumental in the development of the "American Sound" in classical music. He has been described as a modernist, a neoromantic, a neoclass ...

's opera ''

The Mother of Us All ''The Mother of Us All'' is a two-act opera composed by Virgil Thomson to a libretto by Gertrude Stein. Thomson and Stein met in 1945 to begin the writing process, almost twenty years after their first collaborative project, the opera ''Four Sain ...

'' for

New World Records New World Records is a record label that was established in 1975 through a Rockefeller Foundation grant to celebrate America's bicentennial (1976) by producing a 100-LP anthology, with American music from many genres.multi-track recorder, and the analog recording is deemed superior and thus used for the LP release. The backup digital tape was presented at the October 1976 AES Convention in New York, but never commercially released. *1977: Denon develops the smaller portable PCM recording system, the DN-034R. Like the DN-023R it records 8 channels at 47.25 kHz, but it uses 14-bits "with emphasis, making it equivalent to 15.5 bits." It also allowed for overdubbing for the first time, crucial for professional recording. *September 1977: Sony introduces the PCM-1 Audio Unit ($4400 street price ) (44.056 kHz, 14-bit), the first consumer PCM encoder. It required the use of a home video tape recorder for storage. *November 4–7, 1977: 3M demonstrates a prototype 2-channel 50.4 kHz 16-bit digital recorder running on 1-inch tape at at the New York AES Convention. As no true 16-bit converters were available, it combined separate 12-bit and 8-bit converters to create 16-bit performance. *November 28, 1977: Denon brings their DN-034R to

New York City New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...

's Sound Ideas Studios and records

Archie Shepp Archie Shepp (born May 24, 1937) is an American jazz saxophonist, educator and playwright who since the 1960s has played a central part in the development of avant-garde jazz. Biography Early life Shepp was born in Fort Lauderdale, Florida, but ...

's ''On Green Dolphin Street'', making it America's first digitally-recorded commercial album. The following two days, November 29–30, Frank Foster records ''

Manhattan Fever ''Manhattan Fever'' is an album by American jazz saxophonist Frank Foster recorded in 1968 and released on the Blue Note label.

'' which is released April 1978. Five other jazz albums are recorded with the DN-034R in New York before it returns to Japan in December. *January 1978: Soundstream's first commercial release, '' Diahann Carroll With the Duke Ellington Orchestra Under The Direction Of

Mercer Ellington Mercer Kennedy Ellington (March 11, 1919 – February 8, 1996) was an American musician, composer, and arranger. His father was Duke Ellington, whose band Mercer led for 20 years after his father's death. Biography Early life and education Ellin ...

– A Tribute To

Ethel Waters Ethel Waters (October 31, 1896 – September 1, 1977) was an American singer and actress. Waters frequently performed jazz, swing, and pop music on the Broadway stage and in concerts. She began her career in the 1920s singing blues. Her no ...

'', appears *March 1978: Sony introduces the professional-grade

PCM-1600 A PCM adaptor is a device that encodes digital audio as video for recording on a videocassette recorder. The adapter also has the ability to decode a video signal back to digital audio for playback. This digital audio system was used for mas ...

at a list price of US$40,000 () used with an external

U-matic U-matic is an analogue recording Videocassette#Cassette formats, videocassette format first shown by Sony in prototype in October 1969, and introduced to the market in September 1971. It was among the first video formats to contain the vide ...

tape drive, making digital recording commercially available to recording studios for the first time. PCM-1610 and PCM-1630 follow. *April 4–5, 1978:

Telarc Telarc International Corporation is an American audiophile independent record label founded in 1977 by two classically trained musicians and former teachers, Jack Renner (recording engineer), Jack Renner and Robert Woods (producer), Robert Woods. ...

uses Soundstream's PCM system to record Frederick Fennell and his

Eastman Wind Ensemble The Eastman Wind Ensemble was founded by conductor Frederick Fennell at the Eastman School of Music in 1952. The ensemble is often credited with helping redefine the performance of wind band music. At the time, concert bands used all of their pla ...

playing

Gustav Holst Gustav Theodore Holst (born Gustavus Theodore von Holst; 21 September 1874 – 25 May 1934) was an English composer, arranger and teacher. Best known for his orchestral suite ''The Planets'', he composed many other works across a range ...

's ''Suites for Military Band'' and George Frideric Handel's ''

Music for the Royal Fireworks The ''Music for the Royal Fireworks'' ( HWV 351) is a suite in D major for wind instruments composed by George Frideric Handel in 1749 under contract of George II of Great Britain for the fireworks in London's Green Park on 27 April 1749. The ...

.'' When released on LP this became the first US-recorded digital classical release. *June 2, 1978:

Sound 80 Sound 80 is a recording studio in Minneapolis, Minnesota, United States founded by engineer Tom Jung and composer/musician Herb Pilhofer in 1969. Largely involved with local artists, the studio is best known for recording portions of Bob Dylan' ...

studios in Minneapolis records the

Saint Paul Chamber Orchestra The Saint Paul Chamber Orchestra (SPCO) is a full-time professional chamber orchestra based in Saint Paul, Minnesota. In collaboration with five Artistic Partners, the orchestra's musicians present more than 130 concerts and educational programs ea ...

performing

Aaron Copland Aaron Copland (, ; November 14, 1900December 2, 1990) was an American composer, composition teacher, writer, and later a conductor of his own and other American music. Copland was referred to by his peers and critics as "the Dean of American Com ...

's ''

Appalachian Spring ''Appalachian Spring'' is a musical composition by Aaron Copland that was premiered in 1944 and has achieved widespread and enduring popularity as an orchestral suite. The music, scored for a thirteen-member chamber orchestra, was created upon c ...

''. This session is set up as a

direct to disc recording Direct-to-disc recording refers to sound recording methods that bypass the use of magnetic tape recording and record audio directly onto analog disc masters. Professional analog sound recording Most sound recordings for records before the 1950s ...

, with the prototype 3M 50.4 kHz digital recorder running in the background. There is some disagreement, but it appears the resulting LP record (Sound80 Records S80-DLR-101) was taken from the digital backup tapes rather than the direct-to-disc acetate. In 1984 the session is re-released on

by ProArte. This recording was nominated for three

Grammy Award The Grammy Awards (stylized as GRAMMY), or simply known as the Grammys, are awards presented by the Recording Academy of the United States to recognize "outstanding" achievements in the music industry. They are regarded by many as the most pres ...

s, winning " Best Chamber Music Performance" (1980), making it the first digital recording to win a Grammy. *Early June 1978:

records ''

Flim and the BB's Flim & the BB's was a contemporary jazz band that was among the first bands to record albums digitally. History Flim and the BB's consisted of Jimmy Johnson, nicknamed Flim, on Alembic 5-string bass and the two BBs, Bill Berg on percussion an ...

'' debut self-titled album as another

again with the experimental 3M recorder in the background. Again the acetate is deemed not as good as the digital backup, so the digital master is used for the LP record (Sound80 Records S80-DLR-102). This makes it the first U.S. non-classical digital release. Within 6 months the hand-built ("very bulky and finicky") 3M digital recorder is disassembled, rendering the non-standard master tape unplayable. Therefore, no

release is possible. The compact disc release of the Saint Paul Chamber Orchestra, which used the same machine, is unexplained. *March 8, 1979: The first prototype

player is demonstrated by

Philips Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters i ...

in Eindhoven,

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

. Prototype CDs played on the unit were a pressing of Antonio Vivaldi's '' Le quattro stagione'' played by Vittorio Negri and the

Kammerorchester Berlin The Kammerorchester Berlin has been in existence since 1945 and its first director was the conductor Helmut Koch (conductor), Helmut Koch. Already in the 1950s, the orchestra succeeded in making a name for itself. Among other awards it received the ...

(Philips 9500 100, recorded analog 1976), and Joseph Haydn's ''String Quartet No. 31''(?). A third prototype disc, on

Archiv Produktion Archiv Produktion is a classical music record label of German origin. It originated in 1949 as a classical label for the Deutsche Grammophon Gesellschaft (DGG), and in 1958 Archiv was established as a subsidiary of DGG, specialising in recording ...

is pictured but the details are not legible. The text indicates it might be

Franz Schubert Franz Peter Schubert (; 31 January 179719 November 1828) was an Austrian composer of the late Classical and early Romantic eras. Despite his short lifetime, Schubert left behind a vast ''oeuvre'', including more than 600 secular vocal wo ...

's ''

Unfinished Symphony An unfinished symphony is a fragment of a symphony, by a particular composer, that musicians and academics consider incomplete or unfinished for various reasons. The archetypal unfinished symphony is Franz Schubert's Symphony No. 8 (sometimes ...

''.

Herbert von Karajan Herbert von Karajan (; born Heribert Ritter von Karajan; 5 April 1908 – 16 July 1989) was an Austrian conductor. He was principal conductor of the Berlin Philharmonic for 34 years. During the Nazi era, he debuted at the Salzburg Festival, wit ...

and the

Berlin Philharmonic The Berlin Philharmonic (german: Berliner Philharmoniker, links=no, italic=no) is a German orchestra based in Berlin. It is one of the most popular, acclaimed and well-respected orchestras in the world. History The Berlin Philharmonic was fo ...

's recording of Richard Strauss's ''

Eine Alpensinfonie ''An Alpine Symphony'' (''Eine Alpensinfonie''), Op. 64, is a tone poem for large orchestra written by German composer Richard Strauss in 1915. It is one of Strauss's largest non-operatic works; the score calls for about 125 players and a t ...

'' is also mentioned as a contender for earliest test pressing of a CD, but it was not recorded until December 1–3, 1980. *July 11, 1979: The first U.S.-recorded digitally-recorded LP of

popular music Popular music is music with wide appeal that is typically distributed to large audiences through the music industry. These forms and styles can be enjoyed and performed by people with little or no musical training.Popular Music. (2015). ''Fu ...

(with vocals), '' Bop Till You Drop'' by guitarist Ry Cooder, was released by

Warner Bros. Records Warner Records Inc. (formerly Warner Bros. Records Inc.) is an American record label. A subsidiary of the Warner Music Group, it is headquartered in Los Angeles, California. It was founded on March 19, 1958, as the recorded music division of the ...

. The album was recorded in

Los Angeles Los Angeles ( ; es, Los Ángeles, link=no , ), often referred to by its initials L.A., is the List of municipalities in California, largest city in the U.S. state, state of California and the List of United States cities by population, sec ...

on a 32-track digital machine built by the 3M corporation. *August 27, 1979: Giorgio Moroder's '' E=MC²'' is released, the first electronic live-to-digital LP recorded on Soundstream PCM. *October 12, 1979: Fleetwood Mac's ''

Tusk Tusks are elongated, continuously growing front teeth that protrude well beyond the mouth of certain mammal species. They are most commonly canine teeth, as with pigs and walruses, or, in the case of elephants, elongated incisors. Tusks share ...

'' is released on LP. It, and '' Live'', December 8, 1980, were mastered on the Soundstream PCM from analog multi-tracks. *October 30, 1979: Stevie Wonder releases his soundtrack album, ''

Journey Through the Secret Life of Plants Journey or journeying may refer to: * Travel, the movement of people between distant geographical locations ** Day's journey, a measurement of distance ** Road trip, a long-distance journey on the road Animals * Journey (horse), a thoroughbred ra ...

'' recorded and processed on a Sony PCM-1600. *December 1, 1979: The Grammy Award-winning self-titled '' Christopher Cross'' album is released. Cross' album becomes the first digitally recorded album to chart (recorded on the 3M system) in the United States, eventually winning 5 Grammys. Digital recording is now mainstream. *1980: The Red Book standard (44.1 kHz, 16-bit) is established for

Compact Disc Digital Audio Compact Disc Digital Audio (CDDA or CD-DA), also known as Digital Audio Compact Disc or simply as Audio CD, is the standard format for audio compact discs. The standard is defined in the ''Red Book'', one of a series of Rainbow Books (named ...

. *1980: Mitsubishi Electric introduces the X-80

ProDigi Mitsubishi's ProDigi was a professional audio, reel-to-reel, digital audio tape format with a stationary head position, similar to Sony's Digital Audio Stationary Head, which competed against ProDigi when the format was available in the mid- ...

open reel Reel-to-reel audio tape recording, also called open-reel recording, is Magnetic tape#Audio, magnetic tape audio recording in which the recording tape is spooled between reels. To prepare for use, the ''supply reel'' (or ''feed reel'') contain ...

1/4" tape 50.4 kHz 16-bit digital recorder ($5000 ). Only 200 are sold worldwide. *1980: Soundstream merges with Digital Recording Corporation, becoming DRC/Soundstream, to develop and market 50 kHz PCM recording to an optical card. This is subsequently eclipsed by the rise of the 44.1 kHz

and the company is out of business after 1983. *1981: Sony releases the PCM-F1 Digital Audio Processor ($1900 ) (44.056 kHz, 16-bit) and matching SL-2000 Betamax VCR ($700 ) as a complete affordable portable (with optional batteries) home digital recording system *1981: Technics releases the SV-P100 digital audio recorder suitable for both professional (digital mastering) and consumer (home use) recording. It used PCM 14-bit recording on a VHS format cassette tape, resulting in an up to 3 hours programme of 2-channel stereo recording. *August 17, 1982:

Claudio Arrau Claudio Arrau León (; February 6, 1903June 9, 1991) was a Chilean pianist known for his interpretations of a vast repertoire spanning the baroque to 20th-century composers, especially Bach, Beethoven, Schubert, Chopin, Schumann, Liszt and B ...

's March 1979 analog recording of

Frederic Chopin Frederic may refer to: Places United States * Frederic, Wisconsin, a village in Polk County * Frederic Township, Michigan, a township in Crawford County ** Frederic, Michigan, an unincorporated community Other uses * Frederic (band), a Japanese r ...

waltzes (Philips 400 025) becomes the first classical Compact Disc ever commercially manufactured. It is made by the Philips plant in Langenhagen,

Hanover Region Hanover Region (german: Region Hannover) is a district in Lower Saxony, Germany. It is bounded by (from the north and clockwise) the districts of Heidekreis, Celle, Gifhorn, Peine, Hildesheim, Hamelin-Pyrmont, Schaumburg and Nienburg. T ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

. Arrau himself was invited to press the button to start the manufacture. This CD was not actually released until 1983 so it presumably ran into manufacturing problems like the ABBA release (below). *August 17, 1982: The first popular Compact Disc ever manufactured,

ABBA ABBA ( , , formerly named Björn & Benny, Agnetha & Anni-Frid or Björn & Benny, Agnetha & Frida) are a Swedish supergroup formed in Stockholm in 1972 by Agnetha Fältskog, Björn Ulvaeus, Benny Andersson, and Anni-Frid Lyngstad. The group ...

's 1981 album '' The Visitors'' (selected because it was "mostly digitally recorded") is produced at the same plant. However, due to production problems with it the third version didn't actually hit stores until March 1983. *September 5, 1982: Peter Gabriel releases his fourth studio album (titled ''Security'' in North America and ''Peter Gabriel IV'' elsewhere). When released on CD in October 1984 it becomes the first full-digital DDD release. It was recorded on

Sony , commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professiona ...

's Mobile One digital studio and mixed to a Sony PCM-1610. *October 1, 1982: The first

compact disc The compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then released in Oc ...

players are marketed by Sony (CDP-101, $900 ) and Philips (CD-100, $700 ). *October 1, 1982: Billy Joel's analog-recorded '' 52nd Street'' becomes the first CD to hit the market in Japan, beating out ABBA's '' The Visitors'' and Claudio Arrau's Chopin Waltzes. Forty-nine other CDs are released in Japan on the same day including Toto's '' Turn Back'', Pink Floyd's ''

Wish You Were Here Wish You Were Here may refer to: Film, television, and theater Film * ''Wish You Were Here'' (1987 film), a British comedy-drama film by David Leland * ''Wish You Were Here'' (2012 film), an Australian drama/mystery film by Kieran Darcy-Smith ...

'' and

Michael Jackson Michael Joseph Jackson (August 29, 1958 – June 25, 2009) was an American singer, songwriter, dancer, and philanthropist. Dubbed the "King of Pop", he is regarded as one of the most significant cultural figures of the 20th century. Over a ...

's '' Off the Wall''. *October 1982: New England Digital offers the Sample-to-Disk

hard disk recorder A hard disk recorder (HDR) is a system that uses a high-capacity hard disk to record digital audio or digital video. Hard disk recording systems represent an alternative to reel-to-reel audio tape recording and video tape recorders, and provide ...

option on the Synclavier, the first commercial hard disk recording system. *November 26–28, 1982: Flim & the BB's record their second studio album, ''Tricycle''. Released in early 1983, it becomes the first non-classical fully digital CD to be released. (Later given a

SPARS code The SPARS code is a three-position alphabetic classification system developed in the early 1980s by the Society of Professional Audio Recording Services (SPARS) for commercial compact disc releases to denote aspects of the sound recording and re ...

of DD). *March 2, 1983: CD players and 16 CDs from

CBS Records CBS Records may refer to: * CBS Records or CBS/Sony, former name of Sony Music, a global record company * CBS Records International, label for Columbia Records recordings released outside North America from 1962 to 1990 * CBS Records (2006), founde ...

are introduced in the United States. *1984: Sony releases the PCM-501ES

PCM adaptor A PCM adaptor is a device that encodes digital audio as video for recording on a videocassette recorder. The adapter also has the ability to decode a video signal back to digital audio for playback. This digital audio system was used for mast ...

(44.1 kHz, 16-bit) ($895 list price) which is used with an external VHS or Betamax video recorder. *September 1984: Bruce Springsteen's ''

Born in the U.S.A. ''Born in the U.S.A.'' is the seventh studio album by American recording artist Bruce Springsteen, released by Columbia Records on June 4, 1984. It topped the charts in nine countries, including the US and UK, becoming his most commercially su ...

'' becomes the first US-manufactured CD to be released. *12 November 1984: American singer Madonna's second studio album '' Like a Virgin'' is released. It became the first digitally-recorded album that topped the ''Billboard'' 200 chart. *13 May 1985: English rock band Dire Straits' fifth studio album '' Brothers in Arms'' is released. It became the best-selling digitally-recorded album of the 80s, and the first album whose CDs' sales outsold LPs'. *1987: Sony develops Digital Audio Tape. *1989: Test broadcasts for NICAM stereo digital audio for broadcast TV began in the UK. *1990: Digital radio begins in

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

, using the

L-Band The L band is the Institute of Electrical and Electronics Engineers (IEEE) designation for the range of frequencies in the radio spectrum from 1 to 2 gigahertz (GHz). This is at the top end of the ultra high frequency (UHF) band, at the lower ...

. *1991: Alesis Digital Audio Tape ( ADAT) is a tape format used for simultaneously recording eight tracks of digital audio at once, onto Super VHS magnetic tape – a format similar to that used by consumer

VCR A videocassette recorder (VCR) or video recorder is an electromechanical device that records analog audio and analog video from broadcast television or other source on a removable, magnetic tape videocassette, and can play back the recording. ...

s. The product was announced in January 1991 at the

NAMM The NAMM Show is an annual event in the United States that is organized by the National Association of Music Merchants (NAMM), who describe it as "the industry’s largest stage, uniting the global music, sound and entertainment technology commun ...

convention. The first ADAT recorders shipped over a year later in February or March 1992. *1993: Random Access Digital Audio Recorder (

RADAR Radar is a detection system that uses radio waves to determine the distance ('' ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, we ...

) is the first single box device used for simultaneously recording 24 tracks of digital audio at once, onto hard disk drives. The product, manufactured by Creation Technologies was announced in October 1993 at the AES convention in New York. The first RADAR recorders shipped in August 1994. *1996:

Optical disc In computing and optical disc recording technologies, an optical disc (OD) is a flat, usually circular disc that encodes binary data (bits) in the form of pits and lands on a special material, often aluminum, on one of its flat surfaces. ...

s and

DVD player A DVD player is a device that plays DVDs produced under both the DVD-Video and DVD-Audio technical standards, two different and incompatible standards. Some DVD players will also play audio CDs. DVD players are connected to a television to ...

s begin selling in Japan. *1999:

Ricky Martin Enrique Martín Morales (born December 24, 1971), known professionally as Ricky Martin, is a Puerto Rican singer, songwriter, and actor. He is known for his musical versatility, with his Ricky Martin albums discography, discography spanning ...

's "

Livin' la Vida Loca "Livin' la Vida Loca" () is a song recorded by Puerto Rican singer Ricky Martin for his fifth studio album and English-language debut, ''Ricky Martin'' (1999). The song was written by Draco Rosa and Desmond Child, while the production was handl ...

" becomes the first No. 1 single to be recorded, edited, and mixed fully within a

digital audio workstation A digital audio workstation (DAW) is an electronic device or application software used for recording, editing and producing audio files. DAWs come in a wide variety of configurations from a single software program on a laptop, to an integrat ...

. Produced by

Charles Dye Charles Dye is a Grammy-nominated and Latin Grammy-winning record producer, engineer and mixer from Hollywood, Florida, USA. Grammy In 2001, Dye received a Latin Grammy for Best Engineered Album for Thalía's ''Arrasando''. Other production cr ...

and Desmond Child using

Pro Tools Pro Tools is a digital audio workstation (DAW) developed and released by Avid Technology (formerly Digidesign) for Microsoft Windows and macOS. It is used for music creation and production, sound for picture ( sound design, audio post-produ ...

Process

Recording # The analog signal is transmitted from the

input device In computing, an input device is a piece of equipment used to provide data and control signals to an information processing system, such as a computer or information appliance. Examples of input devices include keyboards, mouse, scanners, cameras ...

to an

(ADC). # The ADC converts this signal by repeatedly measuring the momentary level of the analog (audio) wave and then assigning a binary number with a given quantity of bits (word length) to each measurment point. The longer the word length the more precise the representation of the original audio wave level. # The frequency at which the ADC measures the level of the analog wave is called the

sample rate In signal processing, sampling is the reduction of a continuous-time signal to a discrete-time signal. A common example is the conversion of a sound wave to a sequence of "samples". A sample is a value of the signal at a point in time and/or spa ...

or sampling rate. The higher the sampling rate the higher the upper audio frequency of the digitized audio signal. # The ADC outputs a sequence of digital audio samples that make up a continuous stream of 0s and 1s. # These binary numbers are stored on recording media such as magnetic tape, a

hard drive A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magne ...

optical drive In computing, an optical disc drive is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only r ...

or in

solid state memory A solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies to store data persistently, typically using flash memory, and functioning as secondary storage in the hierarchy of computer storage. It is ...

. Playback # The sequence of numbers is transmitted from storage into a

(DAC) # The DAC converts the numbers back to an analog signal by sticking together the level information stored in each digital sample, thus rebuilding the original analog waveform. # This signal is amplified and transmitted to the

loudspeaker A loudspeaker (commonly referred to as a speaker or speaker driver) is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound. A ''speaker system'', also often simply referred to as a "speaker" or ...

Recording of bits

Techniques to record to commercial media

For

digital cassettes Digital audio cassette formats introduced to the professional audio and consumer markets: * Digital Audio Tape (or DAT) is the most well-known, and had some success as an audio storage format among professionals and "prosumers" before the prices ...

, the

tape head A tape head is a type of transducer used in tape recorders to convert electrical signals to magnetic fluctuations and vice versa. They can also be used to read credit/debit/gift cards because the strip of magnetic tape on the back of a credit card ...

moves as well as the tape, typically in a

helical scan Helical scan is a method of recording high-frequency signals on magnetic tape. It is used in open-reel video tape recorders, video cassette recorders, digital audio tape recorders, and some computer tape drives. History Earl E Masterson fro ...

configuration, in order to maintain a high enough speed to keep the bits at a manageable size. For

optical disc recording technologies Optical disc authoring requires a number of different optical disc recorder technologies working in tandem, from the optical disc media to the firmware to the control electronics of the optical disc drive. Types of recordable optical disc The ...

such as

CD-R CD-R (Compact disc-recordable) is a digital optical disc storage format. A CD-R disc is a compact disc that can be written once and read arbitrarily many times. CD-R discs (CD-Rs) are readable by most CD readers manufactured prior to the i ...

, a

laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fi ...

is used to alter the optical properties of the dye layer of the medium. A weaker laser is used to read these patterns.

Parameters of digital audio recording

Word size

The number of

bit The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...

s used to represent a sampled audio wave (the ''

word size In computing, a word is the natural unit of data used by a particular processor design. A word is a fixed-sized datum handled as a unit by the instruction set or the hardware of the processor. The number of bits or digits in a word (the ''word s ...

'') directly affects the resulting

noise Noise is unwanted sound considered unpleasant, loud or disruptive to hearing. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrations through a medium, such as air or water. The difference aris ...

in a recording after intentionally added

dither Dither is an intentionally applied form of noise used to randomize quantization error, preventing large-scale patterns such as color banding in images. Dither is routinely used in processing of both digital audio and video data, and is often ...

, or the

distortion In signal processing, distortion is the alteration of the original shape (or other characteristic) of a signal. In communications and electronics it means the alteration of the waveform of an information-bearing signal, such as an audio signa ...

of an undithered signal. The number of possible voltage levels at the output is simply the number of levels that may be represented by the largest possible digital number (the number 2 raised to the power of the number of bits in each sample). There are no “in between” values allowed. If there are more bits in each sample the waveform is more accurately traced, because each additional bit doubles the number of possible values. The distortion is roughly the percentage that the least significant bit represents out of the average value. Distortion (as a percentage) in digital systems increases as signal levels decrease, which is the opposite of the behavior of analog systems.

Sample rate

If the

is too low, the original audio signal cannot be reconstructed from the sampled signal. As stated by the

, to prevent

aliasing In signal processing and related disciplines, aliasing is an effect that causes different signals to become indistinguishable (or ''aliases'' of one another) when sampled. It also often refers to the distortion or artifact that results when ...

, the audio signal must be sampled at a rate at least twice that of the highest frequency component in the signal. For recording music-quality audio, the following PCM sampling rates are the most common: 44.1, 48, 88.2, 96, 176.4, and 192 kHz, each with an upper-frequency limit half the sampling frequency. When making a recording, experienced audio recording and mastering engineers will often do a master recording at a higher sampling rate (i.e. 88.2, 96, 176.4 or 192 kHz) and then do any editing or mixing at that same higher frequency to avoid aliasing errors. High resolution PCM recordings have been released on

DVD-Audio DVD-Audio (commonly abbreviated as DVD-A) is a digital format for delivering high-fidelity audio content on a DVD. DVD-Audio uses most of the storage on the disc for high-quality audio and is not intended to be a video delivery format. The st ...

(also known as DVD-A), DAD (Digital Audio Disc, which utilizes the stereo PCM audio tracks of a regular DVD),

DualDisc The DualDisc is a type of double-sided optical disc product developed by a group of record companies including Michael Jackson, MJJ Productions Inc., EMI, EMI Music, Universal Music Group, Sony BMG, Sony BMG Music Entertainment, Warner Music Group, ...

(utilizing the DVD-Audio layer), or

High Fidelity Pure Audio High Fidelity Pure Audio, occasionally abbreviated as HFPA, is a marketing initiative, spearheaded by Sony Music Universal Music Group, for audio-only Blu-ray optical discs. Launched in 2013 as a potential successor to the compact disc (CD), i ...

on Blu-ray. In addition it is possible to release a high resolution recording as either an uncompressed

WAV Waveform Audio File Format (WAVE, or WAV due to its filename extension; pronounced "wave") is an audio file format standard, developed by IBM and Microsoft, for storing an audio bitstream on PCs. It is the main format used on Microsoft Wind ...

or lossless compressed FLAC file (usually at 24 bits) without down-converting it. There remains some controversy whether higher sampling rates actually provide any verifiable benefit in the consumer product when using modern anti-aliasing filters. When a

(the CD Red Book standard is 44.1 kHz 16 bit) is to be made from a high-res recording, the recording must be down-converted to 44.1 kHz, or originally recorded at that rate. This is done as part of the mastering process. Beginning in the 1980s, music that was recorded, mixed and/or mastered digitally was often labelled using the

to describe which processes were analog and which were digital. Since digital recording has become near-ubiquitous the SPARS codes are now rarely used.

Error rectification

One of the advantages of digital recording over analog recording is its resistance to errors. Once the signal is in the digital format, it will not be degraded (add noise or distortion) from copying or storage.

References

{{DEFAULTSORT:Digital Recording Sound Video Sound recording