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DictaBelt
The Dictabelt, in early years and much less commonly also called a Memobelt, is an analog audio recording medium commercially introduced by the American Dictaphone company in 1947. Having been intended for recording dictation and other speech for later transcription, it is a write-once-read-many medium consisting of a thick transparent vinyl (according to a 1960s Dictaphone user manual: cellulose acetate butyrate) plastic belt wide and around. The belt is loaded onto a pair of metal cylinders, put under tension, then rotated like a tank tread. It is inscribed with an audio-signal-modulated helical groove by a stylus which is slowly moved across the rotating belt. Unlike the stylus of a record cutter, the Dictabelt stylus is blunt and in recording mode it simply impresses a groove into the plastic rather than engraving it and throwing off a thread of waste material. The Dictabelt system was popular, and by 1952, made up 90% of Dictaphone's sales. Dictabelts were more conv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dictaphone
Dictaphone was an American company founded by Alexander Graham Bell that produced dictation machines. It is now a division of Nuance Communications, based in Burlington, Massachusetts. Although the name "Dictaphone" is a trademark, it has become genericized as a means to refer to any dictation machine. History The Volta Laboratory was established by Alexander Graham Bell in Washington, D.C. in 1881. When the Laboratory's sound-recording inventions were sufficiently developed with the assistance of Charles Sumner Tainter and others, Bell and his associates set up the Volta Graphophone Company, which later merged with the American Graphophone Company (founded in 1887) which itself later evolved into Columbia Records (founded as the Columbia Phonograph Company in 1889). The name "Dictaphone" was trademarked in 1907 by the Columbia Graphophone Company, which soon became the leading manufacturer of such devices. This perpetuated the use for voice recording of wax cyli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phonograph Cylinder
Phonograph cylinders (also referred to as Edison cylinders after its creator Thomas Edison) are the earliest commercial medium for Sound recording and reproduction, recording and reproducing sound. Commonly known simply as "records" in their heyday (c. 1896–1916), a name which has been passed on to Phonograph record, their disc-shaped successor, these hollow cylinder, cylindrical objects have an audio recording engraved on the outside surface which can be reproduced when they are played on a mechanical cylinder phonograph. The first cylinders were wrapped with tin foil but the improved version made of wax was created a decade later, after which they were commercialized. In the 1910s, the competing disc record system Format war, triumphed in the marketplace to become the dominant commercial audio medium. Early development In December 1877, Thomas Edison and his team invented the phonograph using a thin sheet of tin foil wrapped around a hand-cranked, grooved metal cylinder. Tin f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Storage
Sound recording and reproduction is the electrical, Mechanical system, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording technology are analog recording and digital recording. Acoustic analog recording is achieved by a microphone diaphragm that senses changes in atmospheric pressure caused by acoustics, acoustic sound waves and records them as a mechanical representation of the sound waves on a medium such as a phonograph record (in which a stylus cuts grooves on a record). In magnetic tape recording, the sound waves vibrate the microphone diaphragm and are converted into a varying electric current, which is then converted to a varying magnetic field by an electromagnet, which makes a representation of the sound as magnetized areas on a plastic tape with a magnetic coating on it. Analog sound reproduction is the reverse process, with a large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audiovisual Introductions In 1947
Audiovisual (AV) is electronic media possessing both a sound and a visual component, such as slide-tape presentations, films, television programs, corporate conferencing, church services, and live theater productions. Audiovisual service providers frequently offer web streaming, video conferencing, and live broadcast services. The professional audio visual industry has companies that provide hardware, software and services. These organizations are commonly referred to as ''systems integrators'' and perform both the installation and integration of different types of AV equipment from multiple manufacturers into spaces to create the AV experience for the user or audience. Computer-based audiovisual equipment is often used in education, with many schools and universities installing projection equipment and using interactive whiteboard technology. Components Aside from equipment installation, two significant elements of audiovisual are wiring and system control. If either of thes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States House Select Committee On Assassinations
The United States House of Representatives Select Committee on Assassinations (HSCA) was established on September 15, 1976 by U.S. House Resolution 1540 to investigate the assassinations of John F. Kennedy and Martin Luther King Jr. in 1963 and 1968, respectively. The select committee was first formed by the 94th United States Congress, and expired at the end of the 95th Congress. The HSCA completed its investigation in 1978 and issued its final report in 1979, which concluded that Kennedy “was probably assassinated as a result of a conspiracy.” In addition to acoustic analysis of a police channel dictabelt recording, the HSCA also commissioned numerous other scientific studies of assassination-related evidence that corroborate the Warren Commission's findings. However, the HSCA challenged the Warren Commission's conclusion that Lee Harvey Oswald was the only shooter, while stating that it was “unable to identify the other gunman or the extent of the conspiracy.” T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John F
John is a common English name and surname: * John (given name) * John (surname) John may also refer to: New Testament Works * Gospel of John, a title often shortened to John * First Epistle of John, often shortened to 1 John * Second Epistle of John, often shortened to 2 John * Third Epistle of John, often shortened to 3 John People * John the Baptist (died ), regarded as a prophet and the forerunner of Jesus Christ * John the Apostle (died ), one of the twelve apostles of Jesus Christ * John the Evangelist, assigned author of the Fourth Gospel, once identified with the Apostle * John of Patmos, also known as John the Divine or John the Revelator, the author of the Book of Revelation, once identified with the Apostle * John the Presbyter, a figure either identified with or distinguished from the Apostle, the Evangelist and John of Patmos Other people with the given name Religious figures * John, father of Andrew the Apostle and Saint Peter * Pope Jo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gray Audograph
The Gray Audograph was a dictation machine format introduced in 1945. It recorded sound by pressing grooves into soft vinyl discs. The Audograph recorded on thin vinyl discs of 15cm diameter, recording from the inside to the outside, the opposite of conventional gramophone records. Unlike conventional records, the disc was driven by a surface-mounted wheel. This meant that its recording and playback speed decreased toward the edge of the disc (like the Compact Disc and other digital formats), to keep a more constant linear velocity and to improve playing time, which was ten minutes. In 1950, Gray began to make a variant of the Audograph for AT&T AT&T Inc., an abbreviation for its predecessor's former name, the American Telephone and Telegraph Company, is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the w ..., known as the Peatrophone. References External linksRestoring Gray Audograph reco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virginia Circuit Court
The Virginia Circuit Courts are the state trial courts of general jurisdiction in the Commonwealth of Virginia. The Circuit Courts have jurisdiction to hear civil and criminal cases. For civil cases, the courts have authority to try cases with an amount in controversy of more than $4,500 and have exclusive original jurisdiction over claims for more than $25,000. In criminal matters, the Circuit Courts are the trial courts for all felony charges and for misdemeanors originally charged there. The Circuit Courts also have appellate jurisdiction for any case from the Virginia General District Courts (the trial courts of limited jurisdiction in Virginia) claiming more than $50, which are tried ''de novo'' in the Circuit Courts. The state has 120 courts divided among 31 judicial circuits. Judges of the Virginia Circuit Courts are appointed by the legislature, and serve an eight-year term, after which they may be reappointed. The only mandatory qualification for appointment as a Cir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virginia
Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States, Atlantic Coast and the Appalachian Mountains. The state's List of capitals in the United States, capital is Richmond, Virginia, Richmond and its most populous city is Virginia Beach, Virginia, Virginia Beach. Its most populous subdivision is Fairfax County, Virginia, Fairfax County, part of Northern Virginia, where slightly over a third of Virginia's population of more than 8.8million live. Eastern Virginia is part of the Atlantic Plain, and the Middle Peninsula forms the mouth of the Chesapeake Bay. Central Virginia lies predominantly in the Piedmont (United States), Piedmont, the foothill region of the Blue Ridge Mountains, which cross the western and southwestern parts of the state. The fertile Shenandoah Valley fosters the state's mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stylus
A stylus is a writing utensil or tool for scribing or marking into softer materials. Different styluses were used to write in cuneiform by pressing into wet clay, and to scribe or carve into a wax tablet. Very hard styluses are also used to Engraving, engrave metal, and the slate and stylus system is used to punch out dots to write in Braille. Styluses are held in the hand and thus are usually a narrow elongated shape, similar to a modern ballpoint pen. Many styluses are heavily curved to be held more easily. The word ''stylus'' is also used to describe Stylus (computing), computer styluses used to assist in navigating or providing more precision when using touchscreens. Etymology ''Stylus'' comes from the Latin —the spelling ''stylus'' arose from an erroneous connection with Greek (), 'pillar'.''Oxford Latin Dictionary'', s.v. "stilus" (2012). The Latin word had several meanings, including "a long, sharply pointed piece of metal; the stem of a plant; a pointed instrume ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dictation (exercise)
Dictation is the transcription of spoken text: one person who is "dictating" speaks and another who is "taking dictation" writes down the words as they are spoken. Among speakers of several languages, dictation is used as a test of language skill, similar to spelling bees in the English-speaking world. Secondary to teaching language skills, the exercise of dictation has also been used to introduce students to literary works, and to instill morals. Dictation has also been used in an attempt to capture endangered or dying languages, as in the case of Victoria Howard, a Chinook Jargon, Chinook speaker who dictated songs and stories to Melville Jacobs. Etymology It derives from Latin, ''dictāre'' (to assert). Method The exercise requires at least two persons: a reciter and a recorder. The reciter reads a selected text, evenly and clearly and at audible volume, by snippets of multiple words (three to ten or as need be). The text is transcribed by the recorders, as the reciter proce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helix
A helix (; ) is a shape like a cylindrical coil spring or the thread of a machine screw. It is a type of smooth space curve with tangent lines at a constant angle to a fixed axis. Helices are important in biology, as the DNA molecule is formed as two intertwined helices, and many proteins have helical substructures, known as alpha helices. The word ''helix'' comes from the Greek word , "twisted, curved". A "filled-in" helix – for example, a "spiral" (helical) ramp – is a surface called a '' helicoid''. Properties and types The pitch of a helix is the height of one complete helix turn, measured parallel to the axis of the helix. A double helix consists of two (typically congruent) helices with the same axis, differing by a translation along the axis. A circular helix (i.e. one with constant radius) has constant band curvature and constant torsion. The slope of a circular helix is commonly defined as the ratio of the circumference of the circular cylinder that it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
