|Born||December 22, 1933|
|Died||January 6, 2004 70)(aged|
|Awards||AES Gold Medal|
|Institutions|| Soundstream |
University of Utah
|Doctoral students|| Raphael Rom |
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 as well.
Digital audio is sound that has been recorded in, or converted into, digital form. In digital audio, the sound wave of the audio signal is encoded as numerical samples in continuous sequence. For example, in CD audio, samples are taken 44100 times per second each with 16 bit sample depth. Digital audio is also the name for the entire technology of sound recording and reproduction using audio signals that have been encoded in digital form. Following significant advances in digital audio technology during the 1970s, it gradually replaced analog audio technology in many areas of audio engineering and telecommunications in the 1990s and 2000s.
Stockham was born in Passaic, New Jersey.Stockham attended Montclair Kimberley Academy, graduating in the class of 1951. Known as the "father of digital recording", he earned an Sc.D. degree from the Massachusetts Institute of Technology in 1959 and was appointed Assistant Professor of Electrical Engineering. Early in his academic career at MIT, Stockham worked closely with Amar Bose, founder of Bose Corporation, on the use of digital computers for measurement and simulation of room acoustics and for audio recording and enhancement. While at MIT, he noticed several of the students using an MIT Lincoln Laboratory TX-0 mainframe computer installed at the campus to record their voices digitally into the computer's memory, using a microphone and a loudspeaker connected to an A/D-D/A converter attached to the TX-0. This expensive tape recorder led Stockham to his own digital audio experiments on this same computer in 1962.
Passaic is a city in Passaic County, New Jersey, United States. As of the 2010 United States Census, the city had a total population of 69,781, maintaining its status as the 15th largest municipality in New Jersey with an increase of 1,920 residents (+2.8%) from the 2000 Census population of 67,861, which had in turn increased by 9,820 (+16.9%) from the 58,041 counted in the 1990 Census. Passaic is the tenth most densely populated municipality in the entire United States with 22,000+ people per square mile.
Montclair Kimberley Academy (MKA) is a co-educational private school for students in pre-kindergarten through twelfth grade located in Montclair in Essex County, New Jersey, United States. One of New Jersey's largest independent day schools, Montclair Kimberley Academy celebrated the 125th anniversary of the establishment of its earliest component school in 2012. The current school, established in 1974, is the result of the merger of three separate schools: Montclair Academy, a boys' school founded in 1887; The Kimberley School, a girls' school founded in 1906; and Brookside, a coed school founded in 1925.
The Massachusetts Institute of Technology (MIT) is a private research university in Cambridge, Massachusetts. Founded in 1861 in response to the increasing industrialization of the United States, MIT adopted a European polytechnic university model and stressed laboratory instruction in applied science and engineering. The institute is traditionally known for its research and education in the physical sciences and engineering, but more recently in biology, economics, linguistics and management as well. MIT is often ranked among the world's top five universities.
In 1968 he left MIT for the University of Utah, and in 1975 founded Soundstream, Inc. The company developed a 16-bit digital audio recording system using a 16-track Honeywell instrumentation tape recorder as a transport, connected to digital audio recording and playback hardware of Stockham's design. It ran at a sampling rate of 50 kHz, as opposed to the audio CD sampling rate of 44.1 kHz.
The University of Utah is a public research university in Salt Lake City, Utah, United States. As the state's flagship university, the university offers more than 100 undergraduate majors and more than 92 graduate degree programs. The university is classified among "R-1: Doctoral Universities – Highest Research Activity" with "selective" admissions. Graduate studies include the S.J. Quinney College of Law and the School of Medicine, Utah's first medical school. As of Fall 2015, there are 23,909 undergraduate students and 7,764 graduate students, for an enrollment total of 31,673.
Soundstream Inc. was the first audiophile digital audio recording company, providing commercial services for recording and computer-based editing.
Honeywell International Inc. is an American multinational conglomerate company that makes a variety of commercial and consumer products, engineering services and aerospace systems for a wide variety of customers, from private consumers to major corporations and governments. The company operates four business units, known as Strategic Business Units – Honeywell Aerospace, Home and Building Technologies (HBT), Safety and Productivity Solutions (SPS), and Honeywell Performance Materials and Technologies.
Soundstream Inc. was the first commercial digital recording company in the United States, located in Salt Lake City. Stockham was the first to make a commercial digital recording, using his own Soundstream recorder in 1976 at the Santa Fe Opera.[ clarification needed ] In 1980, Soundstream merged with the Digital Recording Company (DRC) and became DRC/Soundstream.
Stockham played a key role in the digital restoration of Enrico Caruso recordings, described in a 1975 IEEE paper.These acoustic recordings were the first to be digitally restored by computer, and were released on the album Caruso - A Legendary Performer, issued in 1976 by RCA Records.
Enrico Caruso was an Italian operatic tenor. He sang to great acclaim at the major opera houses of Europe and the Americas, appearing in a wide variety of roles from the Italian and French repertoires that ranged from the lyric to the dramatic. Caruso also made approximately 260 commercially released recordings from 1902 to 1920. All of these recordings, which span most of his stage career, remain available today on CDs and as downloads and digital streams.
In 1974, he investigated President Richard Nixon's White House tapes, alongside fellow members of the panel of persons nominated jointly by the White House and the Special Prosecution Force. It was he who discovered that the 18 minutes of erasures were not accidental, as Nixon's secretary Rosemary Woods claimed. Stockham was able to discern several distinct erasures and even determined the order of erasure.
Richard Milhous Nixon was the 37th president of the United States from 1969 to 1974. He had previously served as the 36th vice president of the United States from 1953 to 1961, and prior to that as both a U.S. representative and senator from California.
Stockham's team reached agreement on seven conclusions detailed in their 87-page report to Chief Judge John J. Sirica:
1. The erasing and recording operations that produced the buzz
section were done directly on the evidence tape.
2. The Uher 5000 recorder designated Government Exhibit #60 probably produced the entire buzz section.
3. The erasures and buzz recordings were done in at least five, and perhaps as many as nine, separate and contiguous segments.
4. Erasure and recording of each segment required hand operation of keyboard controls on the Uher 5000 machine.
5. Erased portions of the tape probably contained speech originally.
6. Recovery of the speech is not possible by any method known to us.
7. The evidence tape, insofar as we have determined, is an original and not a copy.
Stockham's developments and contributions to digital audio paved the way for later digital audio technologies, such as the audio compact disc and Digital Audio Tape.
Stockham received wide recognition for his pioneering contributions to digital audio. He received, among many others, the Gold Medal award from the Audio Engineering Society in 1987, a Technical Emmy award in 1988, the Poniatoff Gold Medal from the Society of Motion Picture and Television Engineers,a Grammy award from NARAS in 1994, the IEEE Jack S. Kilby Signal Processing Medal in 1998 and a Scientific and Engineering award from the Academy of Motion Picture Arts and Sciences in 1999.
Digital Audio Tape is a signal recording and playback medium developed by Sony and introduced in 1987. In appearance it is similar to a Compact Cassette, using 3.81 mm / 0.15" magnetic tape enclosed in a protective shell, but is roughly half the size at 73 mm × 54 mm × 10.5 mm. As the name suggests, the recording is digital rather than analog. DAT has the ability to record at sampling rates equal to, as well as higher and lower than a CD at 16 bits quantization. If a comparable digital source is copied without returning to the analogue domain, then the DAT will produce an exact clone, unlike other digital media such as Digital Compact Cassette or non-Hi-MD MiniDisc, both of which use a lossy data reduction system.
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 editing capabilities unavailable to tape recorders. Audio HDR systems, which can be standalone or computer-based, typically include provisions for digital mixing and processing of the audio signal.
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 integrated stand-alone unit, all the way to a highly complex configuration of numerous components controlled by a central computer. Regardless of configuration, modern DAWs have a central interface that allows the user to alter and mix multiple recordings and tracks into a final produced piece.
In digital recording, audio signals picked up by a microphone or other transducer or video signals picked up by a camera or similar device are converted into a stream of discrete numbers, representing the changes over time in air pressure for audio, and chroma and luminance values for video, then recorded to a storage device. To play back a digital sound recording, the numbers are retrieved and converted back into their original analog waveforms so that they can be heard through a loudspeaker. To play back a digital video recording, the numbers are retrieved and converted back into their original analog waveforms so that they can be viewed on a video monitor, television or other display.
The Digital Audio Stationary Head or DASH standard is a reel-to-reel, digital audio tape format introduced by Sony in early 1982 for high-quality multitrack studio recording and mastering, as an alternative to analog recording methods. DASH is capable of recording two channels of audio on a quarter-inch tape, and 24 or 48 tracks on 1⁄2-inch-wide (13 mm) tape on open reels of up to 14 inches. The data is recorded on the tape linearly, with a stationary recording head, as opposed to the DAT format, where data is recorded helically with a rotating head, in the same manner as a VCR. The audio data is encoded as linear PCM and boasts strong cyclic redundancy check (CRC) error correction, allowing the tape to be physically edited with a razor blade as analog tape would, e.g. by cutting and splicing, and played back with no loss of signal. In a two-track DASH recorder, the digital data is recorded onto the tape across nine data tracks: eight for the digital audio data and one for the CRC data; there is also provision for two linear analog cue tracks and one additional linear analog track dedicated to recording time code.
Kornelis Antonie "Kees" Schouhamer Immink is a Dutch scientist, inventor, and entrepreneur, who pioneered and advanced the era of digital audio, video, and data recording, including popular digital media such as Compact Disc, DVD and Blu-ray Disc. He has been a prolific and influential engineer, who holds more than 1100 U.S. and international patents. A large portion of the commonly used audio and video playback and recording devices use technologies based on his work. His contributions to coding systems assisted the digital video and audio revolution, by enabling reliable data storage at information densities previously unattainable.
A transport is a device that handles a particular physical storage medium itself, and extracts or records the information to and from the medium, to an outboard set of processing electronics that the transport is connected to.
Robert B. Ingebretsen was a pioneer in the development of digital sound.
The Nixon White House tapes are audio recordings of conversations between U.S. President Richard Nixon and Nixon administration officials, Nixon family members, and White House staff, produced between 1971 and 1973.
James H. McClellan is the Byers Professor of Signal Processing at the Georgia Institute of Technology. He is widely known for his creation of the McClellan transform and for his co-authorship of the Parks–McClellan filter design algorithm.
Thomas Shi-Tao Huang is a researcher and professor emeritus at the University of Illinois at Urbana-Champaign (UIUC). Huang is one of the leading figures in computer vision, pattern recognition and human computer interaction.
Alan Victor Oppenheim is a Professor of Engineering at MIT's Department of Electrical Engineering and Computer Science. He is also a principal investigator in MIT's Research Laboratory of Electronics (RLE), at the Digital Signal Processing Group. His research interests are in the general area of signal processing and its applications. He is coauthor of the widely used textbooks Discrete-Time Signal Processing and Signals and Systems. He is also editor of several advanced books on signal processing.
Expensive Tape Recorder is a digital audio program written by David Gross while a student at the Massachusetts Institute of Technology. Gross developed the idea with Alan Kotok, a fellow member of the Tech Model Railroad Club. The recorder and playback system ran in the late 1950s or early 1960s on MIT's TX-0 computer on loan from Lincoln Laboratory.
Arun N. Netravali is an Indian-American computer engineer credited with major contributions in digital technology including HDTV. He conducted seminal research in digital compression, signal processing and other fields. Netravali was the ninth President of Bell Laboratories and has served as Lucent's Chief Technology Officer and Chief Network Architect. He received his undergraduate degree from IIT Bombay, India, and an M.S. and a Ph.D. from Rice University in Houston, Texas, all in electrical engineering. Several global universities,including the Ecole Polytechnique Federale in Lausanne, Switzerland, have honored him with honorary doctorates.
Multitrack recording of sound is the process in which sound and other electro-acoustic signals are captured on a recording medium such as magnetic tape, which is divided into two or more audio tracks that run parallel with each other. Because they are carried on the same medium, the tracks stay in perfect synchronisation, while allowing multiple sound sources to be recorded asynchronously. The first system for creating stereophonic sound was demonstrated by Clément Ader in Paris in 1881. The pallophotophone, invented by Charles A. Hoxie and first demonstrated in 1922, recorded optically on 35 mm film, and some versions used a format of as many as twelve tracks in parallel on each strip. The tracks were recorded one at a time in separate passes and were not intended for later mixdown or stereophony; as with later half-track and quarter-track monophonic tape recording, the multiple tracks simply multiplied the maximum recording time possible, greatly reducing cost and bulk. British EMI engineer Alan Blumlein patented systems for recording stereophonic sound and surround sound on disc and film in 1933. The history of modern multitrack audio recording using magnetic tape began in 1943 with the invention of stereo tape recording, which divided the recording head into two tracks.
John G. (Jay) McKnight is a co-founder of Magnetic Reference Laboratory (MRL) in San Jose, California, where he was engineering vice-president from 1972 to 1975, and has been the president since 1975. He also develops new products and directs engineering at MRL.
The IEEE Jack S. Kilby Signal Processing Medal is presented "for outstanding achievements in signal processing" theory, technology or commerce. The recipients of this award will receive a gold medal, together with a replica in bronze, a certificate and an honorarium.
Thomas W. Parks is an American electrical engineer and Professor Emeritus of Electrical and Computer Engineering at Cornell University. He is best known for his contributions to digital signal processing, especially digital filter design and computation of the fast Fourier transform. His recent work is in the area of demosaicing.