Elektro is a robot built by J.M. Barnett, Jack Weeks Sr., Harold Gorsuch, and other engineers at the Westinghouse Electric Corporation ' s Mansfield, Ohio , facility between 1937 and 1938.
124-405: Seven feet tall (2.1 m), weighing 265 pounds (120 kg), humanoid in appearance, he could walk by voice command, speak about 700 words (using a 78-rpm record player ), smoke cigarettes, blow up balloons, and move his head and arms. Elektro's body consisted of a steel gear, cam and motor skeleton covered by an aluminum skin. His photoelectric "eyes" could distinguish red and green light. Elektro
248-400: A CD-DA layer. The optophone , first presented in 1931, was an early device that used light for both recording and playback of sound signals on a transparent photograph . More than thirty years later, American inventor James T. Russell has been credited with inventing the first system to record digital media on a photosensitive plate. Russell's patent application was filed in 1966, and he
372-494: A Red Book CD; thus, the mono source material is usually presented as two identical channels in a standard Red Book stereo track (i.e., mirrored mono ); an MP3 CD , can have audio file formats with mono sound. CD-Text is an extension of the Red Book specification for an audio CD that allows for the storage of additional text information (e.g., album name, song name, artist) on a standards-compliant audio CD. The information
496-419: A "cue lever", a device that mechanically lowers the tonearm on to the record. It enables the user to locate an individual track more easily, to pause a record, and to avoid the risk of scratching the record, which may require practice to avoid when lowering the tonearm manually. Early developments in linear turntables were from Rek-O-Kut (portable lathe/phonograph) and Ortho-Sonic in the 1950s, and Acoustical in
620-474: A 150-minute playing time, 44,056 Hz sampling rate, 16-bit linear resolution, and cross-interleaved Reed-Solomon coding (CIRC) error correction code —specifications similar to those later settled upon for the standard compact disc format in 1980. Technical details of Sony's digital audio disc were presented during the 62nd AES Convention, held on 13–16 March 1979, in Brussels . Sony's AES technical paper
744-603: A CD. VCDs are playable in dedicated VCD players, most modern DVD-Video players, personal computers, and some video game consoles. The VCD standard was created in 1993 by Sony, Philips, Matsushita , and JVC and is referred to as the White Book standard. Overall picture quality is intended to be comparable to VHS video. Poorly compressed VCD video can sometimes be of lower quality than VHS video, but VCD exhibits block artifacts rather than analog noise and does not deteriorate further with each use. 352×240 (or SIF ) resolution
868-474: A Graphophone and my mother was a phonograph." Most of the disc machines designed at the Volta Lab had their disc mounted on vertical turntables. The explanation is that in the early experiments, the turntable, with disc, was mounted on the shop lathe, along with the recording and reproducing heads. Later, when the complete models were built, most of them featured vertical turntables. One interesting exception
992-484: A definite method for accomplishing the reproduction. On April 30, 1877, he deposited a sealed envelope containing a summary of his ideas with the French Academy of Sciences , a standard procedure used by scientists and inventors to establish priority of conception of unpublished ideas in the event of any later dispute. An account of his invention was published on October 10, 1877, by which date Cros had devised
1116-400: A device that could replicate the function of the human ear. Scott coated a plate of glass with a thin layer of lampblack . He then took an acoustic trumpet, and at its tapered end affixed a thin membrane that served as the analog to the eardrum . At the center of that membrane, he attached a rigid boar's bristle approximately a centimetre long, placed so that it just grazed the lampblack. As
1240-479: A diameter of 20 cm (7.9 in) and a sound quality superior to that of the vinyl record. However, due to the unsatisfactory performance of the analog format, two Philips research engineers recommended a digital format in March 1974. In 1977, Philips then established a laboratory with the mission of creating a digital audio disc. The diameter of Philips's prototype compact disc was set at 11.5 cm (4.5 in),
1364-541: A different machine that played nonrecordable discs (although Edison's original Phonograph patent included the use of discs. ) In Australian English , "record player" was the term; "turntable" was a more technical term; "gramophone" was restricted to the old mechanical (i.e., wind-up) players; and "phonograph" was used as in British English . The "phonograph" was first demonstrated in Australia on 14 June 1878 to
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#17327839593131488-417: A disc played from beginning to end slows its rotation rate during playback. The program area is 86.05 cm and the length of the recordable spiral is 86.05 cm / 1.6 μm = 5.38 km. With a scanning speed of 1.2 m/s, the playing time is 74 minutes or 650 MiB of data on a CD-ROM. A disc with data packed slightly more densely is tolerated by most players (though some old ones fail). Using
1612-400: A former member of the task force, gives background information on the many technical decisions made, including the choice of the sampling frequency, playing time, and disc diameter. The task force consisted of around 6 persons, though according to Philips, the compact disc was "invented collectively by a large group of people working as a team". Early milestones in the launch and adoption of
1736-469: A graphics signal (typically, the CD+G player is hooked up to a television set or a computer monitor); these graphics are almost exclusively used to display lyrics on a television set for karaoke performers to sing along with. The CD+G format takes advantage of the channels R through W. These six bits store the graphics information. CD + Extended Graphics (CD+EG, also known as CD+XG) is an improved variant of
1860-495: A high quality cartridge and that the surfaces are clean. An alternative approach is to take a high-resolution photograph or scan of each side of the record and interpret the image of the grooves using computer software . An amateur attempt using a flatbed scanner lacked satisfactory fidelity. A professional system employed by the Library of Congress produces excellent quality. Compact disc The compact disc ( CD )
1984-660: A human voice was conducted on April 9, 1860, when Scott recorded someone singing the song " Au Clair de la Lune " ("By the Light of the Moon") on the device. However, the device was not designed to play back sounds, as Scott intended for people to read back the tracings, which he called phonautograms. This was not the first time someone had used a device to create direct tracings of the vibrations of sound-producing objects, as tuning forks had been used in this way by English physicist Thomas Young in 1807. By late 1857, with support from
2108-662: A joint task force of engineers to design a new digital audio disc. After a year of experimentation and discussion, the Red Book CD-DA standard was published in 1980. After their commercial release in 1982, compact discs and their players were extremely popular. Despite costing up to $ 1,000, over 400,000 CD players were sold in the United States between 1983 and 1984. By 1988, CD sales in the United States surpassed those of vinyl LPs, and, by 1992, CD sales surpassed those of prerecorded music-cassette tapes. The success of
2232-563: A joint task force of engineers to design a new digital audio disc. Led by engineers Kees Schouhamer Immink and Toshitada Doi , the research pushed forward laser and optical disc technology. After a year of experimentation and discussion, the task force produced the Red Book CD-DA standard. First published in 1980, the standard was formally adopted by the IEC as an international standard in 1987, with various amendments becoming part of
2356-453: A linear velocity of 1.2 m/s and a narrower track pitch of 1.5 μm increases the playing time to 80 minutes, and data capacity to 700 MiB. Even denser tracks are possible, with semi-standard 90 minute/800 MiB discs having 1.33 μm, and 99 minute/870 MiB having 1.26 μm, but compatibility suffers as density increases. A CD is read by focusing a 780 nm wavelength ( near infrared ) semiconductor laser through
2480-476: A malfunctioning CD writer . Error scanning can reliably predict data losses caused by media deterioration. Support of error scanning differs between vendors and models of optical disc drives , and extended error scanning (known as "advanced error scanning" in Nero DiscSpeed ) has only been available on Plextor and some BenQ optical drives so far, as of 2020. The digital data on a CD begins at
2604-709: A meeting of the Royal Society of Victoria by the Society's Honorary Secretary, Alex Sutherland who published "The Sounds of the Consonants, as Indicated by the Phonograph" in the Society's journal in November that year. On 8 August 1878 the phonograph was publicly demonstrated at the Society's annual conversazione , along with a range of other new inventions, including the microphone . The phonautograph
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#17327839593132728-522: A more direct procedure: the recording stylus could scribe its tracing through a thin coating of acid-resistant material on a metal surface and the surface could then be etched in an acid bath, producing the desired groove without the complication of an intermediate photographic procedure. The author of this article called the device a phonographe , but Cros himself favored the word paleophone , sometimes rendered in French as voix du passé ('voice of
2852-466: A more natural sound on high-quality replay equipment, compared to many digital releases that are highly processed for portable players in high-noise environmental conditions. However, unlike "plug-and-play" digital audio, vinyl record players have user-serviceable parts, which require attention to tonearm alignment and the wear and choice of stylus, the most critical component affecting turntable sound. The terminology used to describe record-playing devices
2976-399: A role in the development of the gramophone , whose inventor, Emile Berliner, worked with the phonautograph in the course of developing his own device. Charles Cros , a French poet and amateur scientist, is the first person known to have made the conceptual leap from recording sound as a traced line to the theoretical possibility of reproducing the sound from the tracing and then to devising
3100-437: A similar machine. On the early phonograph's reproductive capabilities he wrote in retrospect: "It sounded to my ear like someone singing about half a mile away, or talking at the other end of a big hall; but the effect was rather pleasant, save for a peculiar nasal quality wholly due to the mechanism, although there was little of the scratching that later was a prominent feature of the flat disc. Recording for that primitive machine
3224-402: A slightly earlier one that is believed to preserve the voice of U.S. President Rutherford B. Hayes , but as of May 2014 they have not yet been scanned. These antique tinfoil recordings, which have typically been stored folded, are too fragile to be played back with a stylus without seriously damaging them. Edison's 1877 tinfoil recording of Mary Had a Little Lamb , not preserved, has been called
3348-422: A small, simple machine about which few preliminary remarks were offered. The visitor without any ceremony whatever turned the crank, and to the astonishment of all present the machine said: 'Good morning. How do you do? How do you like the phonograph?' The machine thus spoke for itself, and made known the fact that it was the phonograph..." The music critic Herman Klein attended an early demonstration (1881–82) of
3472-480: A stylus with a small diamond or sapphire tip that runs in the record groove. The stylus eventually becomes worn by contact with the groove, and it is usually replaceable. Styli are classified as spherical or elliptical, although the tip is actually shaped as a half-sphere or a half- ellipsoid . Spherical styli are generally more robust than other types, but do not follow the groove as accurately, giving diminished high frequency response. Elliptical styli usually track
3596-460: A variation of this technique called pulse-density modulation (PDM), while Matsushita (now Panasonic ) chose pulse-width modulation (PWM), advertising it as MASH, which is an acronym derived from their patented Multi-stAge noiSe-sHaping PWM topology. The CD was primarily planned as the successor to the vinyl record for playing music, rather than as a data storage medium. However, CDs have grown to encompass other applications. In 1983, following
3720-451: A worm gear is used, a second shorter-throw linear motor, in the form of a coil and magnet, makes fine position adjustments to track eccentricities in the disk at high speed. Some CD drives (particularly those manufactured by Philips during the 1980s and early 1990s) use a swing arm similar to that seen on a gramophone. The pits and lands do not directly represent the 0s and 1s of binary data . Instead, non-return-to-zero, inverted encoding
3844-600: Is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. It uses the Compact Disc Digital Audio format which typically provides 74 minutes of audio on a disc. In later years, the compact disc was adapted for non-audio computer data storage purposes as CD-ROM and its derivatives. First released in Japan in October 1982,
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3968-506: Is described in a document produced in 1980 by the format's joint creators, Sony and Philips. The document is known colloquially as the Red Book CD-DA after the color of its cover. The format is a two-channel 16-bit PCM encoding at a 44.1 kHz sampling rate per channel. Four-channel sound was to be an allowable option within the Red Book format, but has never been implemented. Monaural audio has no existing standard on
4092-409: Is especially important for playback of quadraphonic recordings. A few specialist laser turntables read the groove optically using a laser pickup. Since there is no physical contact with the record, no wear is incurred. However, this "no wear" advantage is debatable, since vinyl records have been tested to withstand even 1200 plays with no significant audio degradation, provided that it is played with
4216-483: Is not uniform across the English-speaking world. In modern contexts, the playback device is often referred to as a "turntable", "record player", or " record changer ". Each of these terms denotes distinct items. When integrated into a DJ setup with a mixer , turntables are colloquially known as "decks". In later versions of electric phonographs, commonly known since the 1940s as record players or turntables,
4340-588: Is often identified as the oldest surviving playable sound recording, although the evidence advanced for its early date is controversial. Wax phonograph cylinder recordings of Handel 's choral music made on June 29, 1888, at The Crystal Palace in London were thought to be the oldest-known surviving musical recordings, until the recent playback by a group of American historians of a phonautograph recording of Au clair de la lune recorded on April 9, 1860. The 1860 phonautogram had not until then been played, as it
4464-407: Is playable in standard CD players, thus making them backward compatible. CD- MIDI is a format used to store music-performance data, which upon playback is performed by electronic instruments that synthesize the audio. Hence, unlike the original Red Book CD-DA, these recordings are not digitally sampled audio recordings. The CD-MIDI format is defined as an extension of the original Red Book . For
4588-510: Is protected by a film of lacquer normally spin coated directly on the reflective layer. The label is printed on the lacquer layer, usually by screen printing or offset printing . CD data is represented as tiny indentations known as pits , encoded in a spiral track molded into the top of the polycarbonate layer. The areas between pits are known as lands . Each pit is approximately 100 nm deep by 500 nm wide, and varies from 850 nm to 3.5 μm in length. The distance between
4712-444: Is routinely extended to 80 minutes and 700 MiB ( 734,003,200 bytes), 90 minutes 800 MiB ( 838,860,800 bytes), or 99 minutes 870 MiB ( 912,261,120 bytes) by arranging data more closely on the same-sized disc. The Mini CD has various diameters ranging from 60 to 80 millimetres (2.4 to 3.1 in); they have been used for CD singles or delivering device drivers . The CD gained rapid popularity in
4836-480: Is stored either in the lead-in area of the CD, where there are roughly five kilobytes of space available or in the subcode channels R to W on the disc, which can store about 31 megabytes. Compact Disc + Graphics is a special audio compact disc that contains graphics data in addition to the audio data on the disc. The disc can be played on a regular audio CD player, but when played on a special CD+G player, it can output
4960-408: Is used: a change from either pit to land or land to pit indicates a 1, while no change indicates a series of 0s. There must be at least two, and no more than ten 0s between each 1, which is defined by the length of the pit. This, in turn, is decoded by reversing the eight-to-fourteen modulation used in mastering the disc, and then reversing the cross-interleaved Reed–Solomon coding , finally revealing
5084-483: The Compact Disc + Graphics (CD+G) format. Like CD+G, CD+EG uses basic CD-ROM features to display text and video information in addition to the music being played. This extra data is stored in subcode channels R-W. Very few CD+EG discs have been published. Super Audio CD (SACD) is a high-resolution, read-only optical audio disc format that was designed to provide higher-fidelity digital audio reproduction than
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5208-522: The Red Book . Introduced in 1999, it was developed by Sony and Philips, the same companies that created the Red Book . SACD was in a format war with DVD-Audio , but neither has replaced audio CDs. The SACD standard is referred to as the Scarlet Book standard. Titles in the SACD format can be issued as hybrid discs; these discs contain the SACD audio stream as well as a standard audio CD layer which
5332-426: The Royal Society of Victoria , writing "There was a large attendance of ladies and gentlemen, who appeared greatly interested in the various scientific instruments exhibited. Among these the most interesting, perhaps, was the trial made by Mr. Sutherland with the phonograph, which was most amusing. Several trials were made, and were all more or less successful. 'Rule Britannia' was distinctly repeated, but great laughter
5456-752: The vinyl revival . During the 2010s, the increasing popularity of solid-state media and music streaming services caused automakers to remove automotive CD players in favor of minijack auxiliary inputs, wired connections to USB devices and wireless Bluetooth connections. Automakers viewed CD players as using up valuable space and taking up weight which could be reallocated to more popular features, like large touchscreens. By 2021, only Lexus and General Motors were still including CD players as standard equipment with certain vehicles. CDs continued to be strong in some markets such as Japan where 132 million units were produced in 2019. The decline in CD sales has slowed in recent years; in 2021, CD sales increased in
5580-716: The 120 mm size was adopted. The adoption of EFM in June 1980 allowed 30 percent more playing time that would have resulted in 97 minutes for 120 mm diameter or 74 minutes for a disc as small as 100 millimetres (3.9 in). Instead, the information density was lowered by 30 percent to keep the playing time at 74 minutes. The 120 mm diameter has been adopted by subsequent formats, including Super Audio CD , DVD , HD DVD , and Blu-ray Disc. The 80-millimetre (3.1 in) diameter discs (" Mini CDs ") can hold up to 24 minutes of music or 210 MiB. The logical format of an audio CD (officially Compact Disc Digital Audio or CD-DA)
5704-422: The 1956 season had ended, Philco decided to discontinue both models, for transistors were too expensive compared to vacuum tubes, but by 1961 a $ 49.95 ($ 509.29 in 2023) portable, battery-powered radio-phonograph with seven transistors was available. There are presently three main phonograph designs: belt-drive , direct-drive , and idler-wheel . In a belt-drive turntable the motor is located off-center from
5828-548: The 1960s, his head was given to Harold Gorsuch, a retiring Westinghouse engineer. In 2013, a replica was exhibited at The Henry Ford Museum in Dearborn, Michigan . Elektro is currently the subject of a property dispute by Weeks' family, Schaut's heirs and the Mansfield Memorial Museum . Phonograph A phonograph , later called a gramophone (as a trademark since 1887, as a generic name in
5952-496: The 1990s, quickly outselling all other audio formats in the United States by 1991, ending the market dominance of the phonograph record and the cassette tape . By 2000, the CD accounted for 92.3% of the entire market share in regard to US music sales . The CD is considered the last dominant audio format of the album era , as the rise of MP3 , iTunes , cellular ringtones , and other downloadable music formats in
6076-611: The 2000s designed as successors to the CD: the Super Audio CD (SACD) and DVD-Audio . However neither of these were adopted partly due to increased relevance of digital (virtual) music and the apparent lack of audible improvements in audio quality to most human ears. These effectively extended the CD's longevity in the music market. With the advent and popularity of Internet-based distribution of files in lossy-compressed audio formats such as MP3 , sales of CDs began to decline in
6200-502: The 2000s. For example, between 2000 and 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%. Despite rapidly declining sales year-over-year, the pervasiveness of the technology lingered for a time, with companies placing CDs in pharmacies, supermarkets, and filling station convenience stores to target buyers less likely to be able to use Internet-based distribution. In 2012, CDs and DVDs made up only 34% of music sales in
6324-502: The 20th century, and phonographs became the first example of home audio that people owned and used at their residences. In the 1960s, the use of 8-track cartridges and cassette tapes were introduced as alternatives. By 1987, phonograph use had declined sharply due to the popularity of cassettes and the rise of the compact disc . However, records have undergone a revival since the late 2000s . This resurgence has much to do with vinyl records' sparing use of audio processing, resulting in
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#17327839593136448-469: The 78-rpm format was completely phased out. (Shellac records were heavier and more brittle.) 33s and 45s were, however, made exclusively of vinyl, with the exception of some 45s manufactured out of polystyrene . In 1955, Philco developed and produced the world's first all- transistor phonograph models TPA-1 and TPA-2, which were announced in the June 28, 1955 edition of The Wall Street Journal . Philco started to sell these all-transistor phonographs in
6572-405: The CD was the second optical disc technology to be invented, after the much larger LaserDisc (LD). By 2007, 200 billion CDs (including audio CDs, CD-ROMs and CD-Rs) had been sold worldwide. Standard CDs have a diameter of 120 mm (4.7 in), and are designed to hold up to 74 minutes of uncompressed stereo digital audio or about 650 MiB ( 681,574,400 bytes) of data. Capacity
6696-467: The CD's introduction, Immink and Joseph Braat presented the first experiments with erasable compact discs during the 73rd AES Convention . In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, recordable CD-R discs were introduced. Recordable CDs became an alternative to tape for recording and distributing music and could be duplicated without degradation in sound quality. Other newer video formats such as DVD and Blu-ray use
6820-475: The DAC. Even when using high-precision components, this approach was prone to decoding errors. Another issue was jitter , a time-related defect. Confronted with the instability of DACs, manufacturers initially turned to increasing the number of bits in the DAC and using several DACs per audio channel, averaging their output. This increased the cost of CD players but did not solve the core problem. A breakthrough in
6944-516: The French Academy of Sciences, claiming due scientific credit for priority of conception. Throughout the first decade (1890–1900) of commercial production of the earliest crude disc records, the direct acid-etch method first invented by Cros was used to create the metal master discs, but Cros was not around to claim any credit or to witness the humble beginnings of the eventually rich phonographic library he had foreseen. He had died in 1888 at
7068-606: The Graphophone, U.S. patent 506,348 , was developed by Tainter in 1893 to compete with nickel-in-the-slot entertainment phonograph U.S. patent 428,750 demonstrated in 1889 by Louis T. Glass, manager of the Pacific Phonograph Company. The work of the Volta Associates laid the foundation for the successful use of dictating machines in business, because their wax recording process
7192-572: The Greek words γράμμα (gramma, meaning 'letter') and φωνή (phōnē, meaning 'voice'). In British English , "gramophone" may refer to any sound-reproducing machine that utilizes disc records . These were introduced and popularized in the UK by the Gramophone Company . Initially, "gramophone" was a proprietary trademark of the company, and any use of the name by competing disc record manufacturers
7316-579: The Société d'encouragement pour l'industrie nationale, Scott's phonautograph was recording sounds with sufficient precision to be adopted by the scientific community, paving the way for the nascent science of acoustics. The device's true significance in the history of recorded sound was not fully realized prior to March 2008, when it was discovered and resurrected in a Paris patent office by First Sounds, an informal collaborative of American audio historians, recording engineers, and sound archivists founded to make
7440-405: The UK since 1910), and since the 1940s a record player , or more recently a turntable , is a device for the mechanical and analogue reproduction of sound . The sound vibration waveforms are recorded as corresponding physical deviations of a helical or spiral groove engraved, etched, incised, or impressed into the surface of a rotating cylinder or disc, called a record . To recreate the sound,
7564-451: The US for the first time since 2004, with Axios citing its rise to "young people who are finding they like hard copies of music in the digital age". It came at the same time as both vinyl and cassette reached sales levels not seen in 30 years. The RIAA reported that CD revenue made a dip in 2022, before increasing again in 2023 and overtook downloading for the first time in over a decade. In
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#17327839593137688-468: The US, 33.4 million CD albums were sold in the year 2022. In France in 2023, 10.5 million CDs were sold, almost double that of vinyl, but both of them represented generated 12% each of the French music industry revenues. Sony and Philips received praise for the development of the compact disc from professional organizations. These awards include: A CD is made from 1.2-millimetre (0.047 in) thick, polycarbonate plastic, and weighs 14–33 grams. From
7812-624: The United States. By 2015, only 24% of music in the United States was purchased on physical media, two thirds of this consisting of CDs; however, in the same year in Japan, over 80% of music was bought on CDs and other physical formats. In 2018, U.S. CD sales were 52 million units—less than 6% of the peak sales volume in 2000. In the UK, 32 million units were sold, almost 100 million fewer than in 2008. In 2018, Best Buy announced plans to decrease their focus on CD sales, however, while continuing to sell records, sales of which are growing during
7936-423: The Volta Associates were sure that they had a number of practical inventions, they filed patent applications and began to seek out investors. The Volta Graphophone Company of Alexandria, Virginia, was created on January 6, 1886, and incorporated on February 3, 1886. It was formed to control the patents and to handle the commercial development of their sound recording and reproduction inventions, one of which became
8060-566: The age of 45. Thomas Edison conceived the principle of recording and reproducing sound between May and July 1877 as a byproduct of his efforts to "play back" recorded telegraph messages and to automate speech sounds for transmission by telephone . His first experiments were with waxed paper. He announced his invention of the first phonograph , a device for recording and replaying sound, on November 21, 1877 (early reports appear in Scientific American and several newspapers in
8184-541: The beginning of November, and an even earlier announcement of Edison working on a "talking-machine" can be found in the Chicago Daily Tribune on May 9 ), and he demonstrated the device for the first time on November 29 (it was patented on February 19, 1878, as US Patent 200,521). "In December, 1877, a young man came into the office of the Scientific American , and placed before the editors
8308-406: The bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. Because the pits are indented into the top layer of the disc and are read through the transparent polycarbonate base, the pits form bumps when read. The laser hits the disc, casting a circle of light wider than the modulated spiral track reflecting partially from
8432-451: The center of the disc and proceeds toward the edge, which allows adaptation to the different sizes available. Standard CDs are available in two sizes. By far, the most common is 120 millimetres (4.7 in) in diameter, with a 74-, 80, 90, or 99-minute audio capacity and a 650, 700, 800, or 870 MiB (737,280,000-byte) data capacity. Discs are 1.2 millimetres (0.047 in) thick, with a 15 millimetres (0.59 in) center hole. The size of
8556-407: The center outward, components are: the center spindle hole (15 mm), the first-transition area (clamping ring), the clamping area (stacking ring), the second-transition area (mirror band), the program (data) area, and the rim. The inner program area occupies a radius from 25 to 58 mm. A thin layer of aluminum or, more rarely, gold is applied to the surface, making it reflective. The metal
8680-450: The compact disc has been credited to the cooperation between Philips and Sony, which together agreed upon and developed compatible hardware. The unified design of the compact disc allowed consumers to purchase any disc or player from any company and allowed the CD to dominate the at-home music market unchallenged. In 1974, Lou Ottens, director of the audio division of Philips, started a small group to develop an analog optical audio disc with
8804-426: The cylinder was rotated and slowly progressed along its axis , the airborne sound vibrated a diaphragm connected to a stylus that indented the foil into the cylinder's groove, thereby recording the vibrations as "hill-and-dale" variations of the depth of the indentation. By 1890, record manufacturers had begun using a rudimentary duplication process to mass-produce their product. While the live performers recorded
8928-423: The diagonal of an audio cassette. Heitaro Nakajima , who developed an early digital audio recorder within Japan's national public broadcasting organization, NHK , in 1970, became general manager of Sony's audio department in 1971. In 1973, his team developed a digital PCM adaptor that made audio recordings using a Betamax video recorder. After this, in 1974 the leap to storing digital audio on an optical disc
9052-581: The earliest sound recordings available to the public. The phonautograms were then digitally converted by scientists at the Lawrence Berkeley National Laboratory in California, who were able to play back the recorded sounds, something Scott had never conceived of. Prior to this point, the earliest known record of a human voice was thought to be an 1877 phonograph recording by Thomas Edison . The phonautograph would play
9176-508: The earliest verified recordings by the famous that have survived to the present. Alexander Graham Bell and his two associates took Edison's tinfoil phonograph and modified it considerably to make it reproduce sound from wax instead of tinfoil. They began their work at Bell's Volta Laboratory in Washington, D. C., in 1879, and continued until they were granted basic patents in 1886 for recording in wax. Although Edison had invented
9300-485: The early 1960s. These were eclipsed by more successful implementations of the concept from the late 1960s through the early 1980s. The pickup or cartridge is a transducer that converts mechanical vibrations from a stylus into an electrical signal. The electrical signal is amplified and converted into sound by one or more loudspeakers . Crystal and ceramic pickups that use the piezoelectric effect have largely been replaced by magnetic cartridges . The pickup includes
9424-494: The fall of 1955, for the price of $ 59.95. The October 1955 issue of Radio & Television News magazine (page 41), had a full page detailed article on Philco's new consumer product. The all-transistor portable phonograph TPA-1 and TPA-2 models played only 45rpm records and used four 1.5 volt "D" batteries for their power supply. The "TPA" stands for "Transistor Phonograph Amplifier". Their circuitry used three Philco germanium PNP alloy-fused junction audio frequency transistors. After
9548-571: The first Dictaphone . After the Volta Associates gave several demonstrations in the City of Washington, businessmen from Philadelphia created the American Graphophone Company on March 28, 1887, in order to produce and sell the machines for the budding phonograph marketplace. The Volta Graphophone Company then merged with American Graphophone, which itself later evolved into Columbia Records . A coin-operated version of
9672-516: The first few years of its existence, the CD was a medium used purely for audio. In 1988, the Yellow Book CD-ROM standard was established by Sony and Philips, which defined a non-volatile optical data computer data storage medium using the same physical format as audio compact discs, readable by a computer with a CD-ROM drive. Video CD (VCD, View CD, and Compact Disc digital video) is a standard digital format for storing video media on
9796-463: The first four UK albums by the Beatles were released in mono on compact disc. The growing acceptance of the CD in 1983 marks the beginning of the popular digital audio revolution. It was enthusiastically received, especially in the early-adopting classical music and audiophile communities, and its handling quality received particular praise. As the price of players gradually came down, and with
9920-549: The first instance of recorded verse . On the occasion of the 50th anniversary of the phonograph, Edison recounted reciting Mary Had a Little Lamb to test his first machine. The 1927 event was filmed by an early sound-on-film newsreel camera, and an audio clip from that film's soundtrack is sometimes mistakenly presented as the original 1877 recording. Wax cylinder recordings made by 19th-century media legends such as P. T. Barnum and Shakespearean actor Edwin Booth are amongst
10044-409: The following year. Alexander Graham Bell 's Volta Laboratory made several improvements in the 1880s and introduced the graphophone , including the use of wax-coated cardboard cylinders and a cutting stylus that moved from side to side in a zigzag groove around the record. In the 1890s, Emile Berliner initiated the transition from phonograph cylinders to flat discs with a spiral groove running from
10168-813: The format included: The first artist to sell a million copies on CD was Dire Straits , with their 1985 album Brothers in Arms . One of the first CD markets was devoted to reissuing popular music whose commercial potential was already proven. The first major artist to have their entire catalog converted to CD was David Bowie , whose first fourteen studio albums (up to Scary Monsters (and Super Creeps) ) of (then) sixteen were made available by RCA Records in February 1985, along with four greatest hits albums; his fifteenth and sixteenth albums ( Let's Dance and Tonight , respectively) had already been issued on CD by EMI Records in 1983 and 1984, respectively. On 26 February 1987,
10292-407: The glass plate was slid horizontally in a well formed groove at a speed of one meter per second, a person would speak into the trumpet, causing the membrane to vibrate and the stylus to trace figures that were scratched into the lampblack. On March 25, 1857, Scott received the French patent #17,897/31,470 for his device, which he called a phonautograph. The earliest known surviving recorded sound of
10416-410: The groove more accurately, with increased high frequency response and less distortion. For DJ use, the relative robustness of spherical styli make them generally preferred for back-cuing and scratching. There are a number of derivations of the basic elliptical type, including the shibata or fine line stylus, which can more accurately reproduce high frequency information contained in the record groove. This
10540-476: The hard rubber used to make the discs with a shellac compound. Berliner's early records had poor sound quality, however. Work by Eldridge R. Johnson eventually improved the sound fidelity to a point where it was as good as the cylinder. In the 1930s, vinyl (originally known as vinylite) was introduced as a record material for radio transcription discs , and for radio commercials. At that time, virtually no discs for home use were made from this material. Vinyl
10664-530: The hole was chosen by Joop Sinjou and based on a Dutch 10-cent coin: a dubbeltje . Philips/Sony patented the physical dimensions. The official Philips history says the capacity was specified by Sony executive Norio Ohga to be able to contain the entirety of Beethoven's Ninth Symphony on one disc. This is a myth according to Kees Immink , as the EFM code format had not yet been decided in December 1979, when
10788-505: The introduction of the portable Discman , the CD began to gain popularity in the larger popular and rock music markets. With the rise in CD sales, pre-recorded cassette tape sales began to decline in the late 1980s; CD sales overtook cassette sales in the early 1990s. In 1988, 400 million CDs were manufactured by 50 pressing plants around the world. Early CD players employed binary-weighted digital-to-analog converters (DAC), which contained individual electrical components for each bit of
10912-476: The label side of the disc. Scratches on the clear side can be repaired by refilling them with similar refractive plastic or by careful polishing. The edges of CDs are sometimes incompletely sealed, allowing gases and liquids to enter the CD and corrode the metal reflective layer and/or interfere with the focus of the laser on the pits, a condition known as disc rot . The fungus Geotrichum candidum has been found—under conditions of high heat and humidity—to consume
11036-510: The lands and partially from the top of any bumps where they are present. As the laser passes over a pit (bump), its height means that the round trip path of the light reflected from its peak is 1/2 wavelength out of phase with the light reflected from the land around it. This is because the height of a bump is around 1/4 of the wavelength of the light used, so the light falls 1/4 out of phase before reflection and another 1/4 wavelength out of phase after reflection. This causes partial cancellation of
11160-419: The laser's reflection from the surface. By measuring the reflected intensity change with a photodiode , a modulated signal is read back from the disc. To accommodate the spiral pattern of data, the laser is placed on a mobile mechanism within the disc tray of any CD player. This mechanism typically takes the form of a sled that moves along a rail. The sled can be driven by a worm gear or linear motor . Where
11284-428: The late 1980s culminated in development of the 1-bit DAC , which converts high-resolution low-frequency digital input signal into a lower-resolution high-frequency signal that is mapped to voltages and then smoothed with an analog filter. The temporary use of a lower-resolution signal simplified circuit design and improved efficiency, which is why it became dominant in CD players starting from the early 1990s. Philips used
11408-400: The master phonograph, up to ten tubes led to blank cylinders in other phonographs. Until this development, each record had to be custom-made. Before long, a more advanced pantograph -based process made it possible to simultaneously produce 90–150 copies of each record. However, as demand for certain records grew, popular artists still needed to re-record and re-re-record their songs. Reportedly,
11532-566: The matrixes to stamp disc can be shipped to other printing plants for a global distribution of recordings; cylinders could not be stamped until 1901–1902, when the gold moulding process was introduced by Edison. Through experimentation, in 1892 Berliner began commercial production of his disc records and "gramophones". His " phonograph record " was the first disc record to be offered to the public. They were five inches (13 cm) in diameter and recorded on one side only. Seven-inch (17.5 cm) records followed in 1895. Also in 1895 Berliner replaced
11656-492: The medium's first major African-American star George Washington Johnson was obliged to perform his " The Laughing Song " (or the separate "The Whistling Coon") up to thousands of times in a studio during his recording career. Sometimes he would sing "The Laughing Song" more than fifty times in a day, at twenty cents per rendition. (The average price of a single cylinder in the mid-1890s was about fifty cents.) Lambert 's lead cylinder recording for an experimental talking clock
11780-557: The mid-2000s ended the decade-long dominance of the CD. The format was later adapted (as CD-ROM ) for general purpose data storage and initially could hold much more data than a personal computer hard disk drive . Several other formats were further derived, both pre-pressed and blank user writable, including write-once audio and data storage ( CD-R ), rewritable media ( CD-RW ), Video CD (VCD), Super Video CD (SVCD), Photo CD , Picture CD , Compact Disc-Interactive ( CD-i ), Enhanced Music CD , and Super Audio CD (SACD) which may have
11904-473: The movements of the stylus are transformed into an electrical signal by a transducer . This signal is then converted back into sound through an amplifier and one or more loudspeakers . The term "phonograph", meaning "sound writing", originates from the Greek words φωνή (phonē, meaning 'sound' or 'voice') and γραφή (graphē, meaning 'writing'). Similarly, the terms "gramophone" and "graphophone" have roots in
12028-464: The next five years developing the New York City electric light and power system. Meanwhile, Bell, a scientist and experimenter at heart, was looking for new worlds to conquer after having patented the telephone . According to Sumner Tainter , it was through Gardiner Green Hubbard that Bell took up the phonograph challenge. Bell had married Hubbard's daughter Mabel in 1879 while Hubbard
12152-471: The past'). Cros was a poet of meager means, not in a position to pay a machinist to build a working model, and largely content to bequeath his ideas to the public domain free of charge and let others reduce them to practice, but after the earliest reports of Edison's presumably independent invention crossed the Atlantic he had his sealed letter of April 30 opened and read at the December 3, 1877 meeting of
12276-401: The periphery to near the centre, coining the term gramophone for disc record players, which is predominantly used in many languages. Later improvements through the years included modifications to the turntable and its drive system, stylus, pickup system, and the sound and equalization systems. The disc phonograph record was the dominant commercial audio distribution format throughout most of
12400-496: The phonograph in 1877, the fame bestowed on him for this invention was not due to its efficiency. Recording with his tinfoil phonograph was too difficult to be practical, as the tinfoil tore easily, and even when the stylus was properly adjusted, its reproduction of sound was distorted, and good for only a few playbacks; nevertheless Edison had discovered the idea of sound recording . However immediately after his discovery he did not improve it, allegedly because of an agreement to spend
12524-483: The platter, either underneath it or entirely outside of it, and is connected to the platter or counter-platter by a drive belt made from elastomeric material. The direct-drive turntable was invented by Shuichi Obata, an engineer at Matsushita (now Panasonic). In 1969, Matsushita released it as the Technics SP-10, the first direct-drive turntable on the market. The most influential direct-drive turntable
12648-536: The polycarbonate plastic and aluminium found in CDs. The data integrity of compact discs can be measured using surface error scanning , which can measure the rates of different types of data errors, known as C1 , C2 , CU and extended (finer-grain) error measurements known as E11 , E12 , E21 , E22 , E31 and E32 , of which higher rates indicate a possibly damaged or unclean data surface, low media quality, deteriorating media and recordable media written to by
12772-507: The prior art by Optophonie and James Russell, the information on the disc is read from a reflective layer using a laser as a light source through a protective substrate. Prototypes were developed by Philips and Sony independently in the late 1970s. Although originally dismissed by Philips Research management as a trivial pursuit, the CD became the primary focus for Philips as the LaserDisc format struggled. In 1979, Sony and Philips set up
12896-543: The raw data stored on the disc. These encoding techniques (defined in the Red Book ) were originally designed for CD Digital Audio , but they later became a standard for almost all CD formats (such as CD-ROM ). CDs are susceptible to damage during handling and from environmental exposure. Pits are much closer to the label side of a disc, enabling defects and contaminants on the clear side to be out of focus during playback. Consequently, CDs are more likely to suffer damage on
13020-432: The same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CDs. CD sales in the United States peaked by 2000. By the early 2000s, the CD player had largely replaced the audio cassette player as standard equipment in new automobiles, with 2010 being the final model year for any car in the United States to have a factory-equipped cassette player. Two new formats were marketed in
13144-511: The standard in 1996. Philips coined the term compact disc in line with another audio product, the Compact Cassette , and contributed the general manufacturing process , based on video LaserDisc technology. Philips also contributed eight-to-fourteen modulation (EFM), while Sony contributed the error-correction method, CIRC, which offers resilience to defects such as scratches and fingerprints. The Compact Disc Story , told by
13268-543: The stylus, which thus described a spiral, recording 150 grooves to the inch. The basic distinction between the Edison's first phonograph patent and the Bell and Tainter patent of 1886 was the method of recording. Edison's method was to indent the sound waves on a piece of tin foil, while Bell and Tainter's invention called for cutting, or "engraving", the sound waves into a wax record with a sharp recording stylus. In 1885, when
13392-444: The surface is similarly rotated while a playback stylus traces the groove and is therefore vibrated by it, faintly reproducing the recorded sound. In early acoustic phonographs, the stylus vibrated a diaphragm that produced sound waves coupled to the open air through a flaring horn , or directly to the listener's ears through stethoscope -type earphones. The phonograph was invented in 1877 by Thomas Edison ; its use would rise
13516-420: The windings (the pitch ) is 1.6 μm (measured center-to-center, not between the edges). When playing an audio CD, a motor within the CD player spins the disc to a scanning velocity of 1.2–1.4 m/s ( constant linear velocity , CLV)—equivalent to approximately 500 RPM at the inside of the disc, and approximately 200 RPM at the outside edge. The track on the CD begins at the inside and spirals outward so
13640-548: Was a comparatively simple matter. I had to keep my mouth about six inches away from the horn and remember not to make my voice too loud if I wanted anything approximating to a clear reproduction; that was all. When it was played over to me and I heard my own voice for the first time, one or two friends who were present said that it sounded rather like mine; others declared that they would never have recognised it. I daresay both opinions were correct." The Argus newspaper from Melbourne, Australia, reported on an 1878 demonstration at
13764-441: Was a horizontal seven inch turntable. The machine, although made in 1886, was a duplicate of one made earlier but taken to Europe by Chichester Bell . Tainter was granted U.S. patent 385,886 on July 10, 1888. The playing arm is rigid, except for a pivoted vertical motion of 90 degrees to allow removal of the record or a return to starting position. While recording or playing, the record not only rotated, but moved laterally under
13888-413: Was caused by the repetition of the convivial song of 'He's a jolly good fellow,' which sounded as if it was being sung by an old man of 80 with a cracked voice." Edison's early phonographs recorded onto a thin sheet of metal, normally tinfoil , which was temporarily wrapped around a helically grooved cylinder mounted on a correspondingly threaded rod supported by plain and threaded bearings . While
14012-656: Was displayed at Pacific Ocean Park in Ocean Park , Santa Monica, California , "which was in operation from 1958 to 1967, as part of the House of Tomorrow exhibit . Elektro appeared as "Thinko", in Sex Kittens Go to College (1960). Sparko's fate is unknown. All original pieces of Elektro were eventually located and restored. Today, he is on display at The Mansfield Memorial Museum in Mansfield, Ohio . In
14136-464: Was easily made. Sony first publicly demonstrated an optical digital audio disc in September 1976. A year later, in September 1977, Sony showed the press a 30 cm (12 in) disc that could play an hour of digital audio (44,100 Hz sampling rate and 16-bit resolution) using modified frequency modulation encoding. In September 1978, the company demonstrated an optical digital audio disc with
14260-461: Was granted a patent in 1970. Following litigation, Sony and Philips licensed Russell's patents for recording in 1988. It is debatable whether Russell's concepts, patents, and prototypes instigated and in some measure influenced the compact disc's design. The compact disc is an evolution of LaserDisc technology, where a focused laser beam is used that enables the high information density required for high-quality digital audio signals. Unlike
14384-605: Was invented on March 25, 1857, by Frenchman Édouard-Léon Scott de Martinville , an editor and typographer of manuscripts at a scientific publishing house in Paris. One day while editing Professor Longet's Traité de Physiologie , he happened upon that customer's engraved illustration of the anatomy of the human ear, and conceived of "the imprudent idea of photographing the word." In 1853 or 1854 (Scott cited both years) he began working on "le problème de la parole s'écrivant elle-même" ("the problem of speech writing itself"), aiming to build
14508-618: Was on exhibit at the 1939 New York World's Fair and was joined at that fair in 1940, with "Sparko", a robot dog that could bark, sit, and beg to humans. Several minutes of color sound footage of Elektro in action can be seen at 33:55 in the movie, The Middleton Family at the New York World's Fair , a fully-produced hour-long movie made by Westinghouse, which showcased the Westinghouse pavilion. Elektro toured North America in 1950 in promotional appearances for Westinghouse, and
14632-592: Was only a transcription of sound waves into graphic form on paper for visual study. Recently developed optical scanning and image processing techniques have given new life to early recordings by making it possible to play unusually delicate or physically unplayable media without physical contact. A recording made on a sheet of tinfoil at an 1878 demonstration of Edison's phonograph in St. Louis, Missouri, has been played back by optical scanning and digital analysis. A few other early tinfoil recordings are known to survive, including
14756-443: Was practical and their machines were durable. But it would take several more years and the renewed efforts of Edison and the further improvements of Emile Berliner and many others, before the recording industry became a major factor in home entertainment . Discs are not inherently better than cylinders at providing audio fidelity. Rather, the advantages of the format are seen in the manufacturing process: discs can be stamped, and
14880-601: Was president of the Edison Speaking Phonograph Co., and his organization, which had purchased the Edison patent, was financially troubled because people did not want to buy a machine that seldom worked well and proved difficult for the average person to operate. The sound vibrations had been indented in the wax that had been applied to the Edison phonograph. The following was the text of one of their recordings: "There are more things in heaven and earth, Horatio, than are dreamed of in your philosophy. I am
15004-514: Was published on 1 March 1979. A week later, on 8 March, Philips publicly demonstrated a prototype of an optical digital audio disc at a press conference called "Philips Introduce Compact Disc" in Eindhoven , Netherlands. Sony executive Norio Ohga , later CEO and chairman of Sony, and Heitaro Nakajima were convinced of the format's commercial potential and pushed further development despite widespread skepticism. In 1979, Sony and Philips set up
15128-410: Was rigorously challenged in court. However, in 1910, an English court decision ruled that the term had become generic; In American English , "phonograph", properly specific to machines made by Edison, was sometimes used in a generic sense as early as the 1890s to include cylinder-playing machines made by others. But it was then considered strictly incorrect to apply it to Emile Berliner 's Gramophone,
15252-669: Was the Technics SL-1200 , which, following the spread of turntablism in hip hop culture, became the most widely-used turntable in DJ culture for several decades. In some high quality equipment the arm carrying the pickup, known as a tonearm, is manufactured separately from the motor and turntable unit. Companies specialising in the manufacture of tonearms include the English company SME . More sophisticated turntables were (and still are) frequently manufactured so as to incorporate
15376-399: Was used for the popular 78-rpm V-discs issued to US soldiers during World War II . This significantly reduced breakage during transport. The first commercial vinylite record was the set of five 12" discs " Prince Igor " (Asch Records album S-800, dubbed from Soviet masters in 1945). Victor began selling some home-use vinyl 78s in late 1945; but most 78s were made of a shellac compound until
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