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Article

Murray Campbell

(Graham)

(b Portland, OR, April 29, 1911; d Los Angeles, Oct 28, 1988). American acoustician. After studying at Reed College, Portland (BA 1932), he undertook postgraduate study at the University of California in Berkeley (MA 1936, PhD 1940). His early research work was in nuclear physics, working under the supervision of Ernest Lawrence in the Radiation Laboratory at Berkeley. In 1945 he was appointed professor of physics at the University of Southern California, and he continued in that post until his retirement in 1980. An accomplished performer on the piano and the bassoon, Backus was awarded the degree of MMus in conducting by the University of Southern California in 1959. In the later stages of his research career he made major contributions to the study of the acoustics of woodwind instruments, brass instruments and organ pipes. In 1969 the first edition of The Acoustical Foundations of Music...

Article

Murray Campbell

(Henry)

(b Chicago, Jan 2, 1925; d Cleveland, Aug 4, 1987). American acoustician. His parents being missionaries, he spent much of his childhood in Lahore. After returning to the USA to study at Washington University, St Louis (AB 1948, PhD 1952), Benade was appointed in 1952 to the physics faculty at Case Institute of Technology, Cleveland, which later became Case Western Reserve University. Promoted to a full professorship in 1969, he continued in that post until shortly before his death. A skilled woodwind player, he had an exceptional ability to relate the results of acoustical research to the practical requirements of musicians and musical instrument makers. Benade established a research programme which made many fundamental contributions to the understanding of the operation of wind instruments. Also active in string instrument research, he was a founding member of the Catgut Acoustical Society and its president between 1969 and 1972...

Article

Clive Greated

(b Cleveland, July 19, 1915). American physicist and acoustician. After studying physics at the Case School of Applied Science (BS 1937) he obtained the PhD from the University of Illinois. From 1941 to 1980 he held various research and management positions at the Westinghouse Corp. His research into the acoustics of the flute, carried out in a small laboratory at his home, has contributed significantly to what is known today about the behaviour of flutes and organ pipes. Several of his papers are recognised as standard reference material. His theory of feedback and how this relates to the means by which the flautist produces the desired frequencies and loudness is particularly relevant to performance. He also studied the significance of mouth resonance and the effect of mode stretching on harmonic generation. His work on the intonation of both antique and modern flutes and his critical assessment of Theobald Boehm's methods have helped in shaping current views on the historical development of the instrument....

Article

Murray Campbell

(b Cleveland, OH, July 19, 1915; d Pittsburgh, PA, Feb 10, 2010). American scientist and acoustician. After studying physics at Case Institute of Technology (BS 1937), he carried out research in nuclear physics at the University of Illinois (PhD 1941). He then joined the Westinghouse Electric Corporation, remaining with the firm for the rest of his professional life; he retired in 1980 after a distinguished career culminating in six years as Director of Research and Development. In his youth he had become an accomplished flute player, and during his undergraduate studies at Case he encountered the notable acoustician Dayton C. Miller. This meeting led to a lifelong interest in the acoustics of the flute, and Coltman developed a laboratory at his home in which he conducted many important and illuminating experiments on flutes and flute playing. Particularly significant was his contribution to the understanding of the subtle interaction between the air jet blown across the flute embouchure hole by the player and the resonances of the air column within the flute pipe. Over four decades, starting in the mid-1960s, he published more than 40 papers on the acoustics of flutes and organ pipes. He was a member of the National Academy of Engineering and a Fellow of the American Physical Society and the Institute of Electrical and Electronic Engineers....

Article

Charles Garrett

Music associated with the Creole people, of mixed European and African descent, in the gulf region of the United States, particularly Louisiana. For further discussion see articles on Jazz , New orleans , New orleans music , Swamp pop , and Zydeco . louis moreau Gottschalk integrated Creole folk music into his compositions. Well-known Creole musicians include ...

Article

William Brooks and George L. Frow

(Alva)

(b Milan, OH, Feb 11, 1847; d West Orange, NJ, Oct 18, 1931). American inventor. He had only a few months of formal schooling before becoming successively a newsboy, a food hawker on trains and a telegraph operator. In 1870, with money received from the sale of telegraphic inventions, he founded a research laboratory. There he constructed the carbon telephone transmitter (1876), the cylinder phonograph (1877) and the first practical electric light (1879). These devices brought him instant fame, and he spent much of the rest of his life in their improvement; he also aided the creation of the myth that surrounds his achievements. The phonograph was a badly flawed novelty when it was first introduced, and Edison abandoned it until the late 1880s when, challenged by Charles Tainter’s graphophone, he organized his own recording company. Although he portrayed himself as financially naive, Edison displayed ruthlessness and skill in the subsequent battles between companies. He clung stubbornly to his original ideas, accepting such innovations as disc records and spring-driven machines only under the pressure of competition. He also held strong opinions about music, despite his congenital deafness, and these sometimes adversely affected his choice of artists. Although his vision of the phonograph as a viable recording device for music was largely realized by others, Edison continues to be regarded, in the public mind, as the creator of the recording industry....

Article

Murray Campbell

(b Provo, UT, Sept 11, 1884; d Provo, July 23, 1981). American acoustician. He studied at Brigham Young University in Provo (BS 1907), then at the University of Chicago, where he gained his doctorate in 1911 for research into the charge of the electron. In 1916 he joined the staff of Bell Telephone Laboratories in New York; he remained there for 33 years, becoming director of acoustical research in 1928 and of physical research in 1935. In 1949 Fletcher was appointed professor of electrical engineering at Columbia University, and in 1952 he returned to Brigham Young University as director of research. He became professor emeritus in 1974, and continued his research activity until his death. Fletcher was one of the great pioneers of the science of psychoacoustics, and his work on the human perception of sound was of fundamental importance. Responsible for the first public demonstration of stereophonic sound reproduction in ...

Article

(b Detroit, MI, June 20, 1917; d New York, NY, Jan 4, 2011). American acoustician. At UCLA he studied mathematics and physics (BA 1938, MA 1940), then went to the Massachusetts Institute of Technology to study acoustics under Philip McCord Morse (PhD 1945). In posts at Bell Telephone Laboratories (1945–51) and Columbia University (from 1952), where he taught in the engineering school as well as the graduate school of architecture and planning, he researched the acoustical properties of building materials, airborne sound, and musical instruments. He was acoustical consultant for more than 100 halls, including the Metropolitan Opera House (1966); Powell Symphony Hall, St. Louis (renovation 1968); Great Hall, Krannert Center for the Performing Arts, University of Illinois (1969); the concert hall and opera house at the John F. Kennedy Center (1971); Orchestra Hall, Minneapolis (...

Article

Alex U. Case

Form factors for loudspeakers designed for proximity to the ear. Ear buds and in-ear headphones are inserted into the ear canal, circum-aural headphones fit over the entire outer ear, and supra-aural headphones are placed against the outer ear. The addition of a microphone near the mouth produces a headset useful for two-way communication.

Two important implications of the closeness of the loudspeaker drivers to the ears are binaural listening and electro-acoustic efficiency. Binaural listening, in which each ear receives a dedicated signal without inter-aural crosstalk and devoid of the acoustic signature of the actual listening space, is essential to some forms of audio research and opens the door to the creation of new perceived environments through a range of signal processing techniques focused on the localization and spatialization of sound. Headphones need only a small fraction of the sound power required by traditional loudspeaker enclosures placed at a distance, and this efficiency is crucial for the portability of battery-powered devices....

Article

D. Quincy Whitney

(b Springfield, MA, May 24, 1911; d Wolfeboro, NH, Aug 7, 2009). American violinmaker, acoustician, and writer. A trumpeter and biology graduate of Cornell University (AB 1933) and New York University (MA 1942), she left both disciplines to embrace string instruments and acoustical physics. While teaching science and woodworking at the Brearley School, chamber music colleagues convinced her to take up viola. A woodcarver since childhood, Hutchins, at age 35, decided to make a viola. Hutchins then studied luthiery with Karl A. Berger (1949–59) and Stradivari expert Fernando Sacconi. While she and Harvard physicist Frederick A. Saunders performed more than 100 acoustical experiments (1949–63), Hutchins taught herself acoustical physics by making string instruments. In 1963 Hutchins and colleagues Robert Fryxell and John Schelleng founded the Catgut Acoustical Society. She published the CAS journal for more than 30 years, helping bridge the gap between violin makers and acoustical physicists. Hutchins made more than 500 instruments, authored more than 100 technical papers on violin acoustics, and edited ...

Article

Alex U. Case

A transducer that converts a signal from the electrical domain into the acoustical, transforming a pattern of changing electrical voltages into a similar pattern of changing air pressures.

Whenever electricity flows, it is accompanied by a magnetic field. Play an audio signal through a wire, and a changing magnetic field forms around it, a magnetic analogy for the electrical variations within. Let that wire’s changing magnetism interact with a fixed magnetic field and it will be pushed and pulled back and forth, a mechanical realization of the electrical signal. When that conductor has a flat ribbon shape, it can energize the air directly and is the basis for a ribbon loudspeaker. Make the conductor a coil of wire and attach it to a piston light enough to vibrate quickly, yet rigid enough to move the air around it, and a moving coil loudspeaker is born.

The loudspeaker driver is often enclosed in a box, with the practical benefit of protecting the components and the acoustical effect of influencing its spectral resonance. Multiple loudspeakers, each optimized for performance in a specific frequency range, may be assembled into a single loudspeaker system whose total output is the sum of the behaviors of the individual speakers—woofers for low frequencies, tweeters for high frequencies, and midrange drivers in between. Subwoofers are systems designed specifically for the lowest frequencies. The electronic crossover circuitry spectrally divides the signal among the specific drivers in a multi-way loudspeaker system. Horns may be fitted on a driver for more efficient and more directional sound radiation. Very small loudspeakers placed over the ear or in the ear canal make-up headphones and ear buds. The loudspeaker is an essential element of some of the most important musical instruments in contemporary popular music styles: DJ mixers, synthesizers, and electric guitars. In addition to material science and manufacturing innovations, loudspeaker development relies increasingly on digital signal processing for detailed measurements, high quality filtering, and room correction....

Article

R.W.B. Stephens

revised by James F. Bell and Murray Campbell

( b Strongsville, OH, March 13, 1866; d Cleveland, Feb 22, 1941). American acoustician . He studied at Princeton (DSc 1890) and held appointments there before becoming head of the physics department at the Case School of Applied Science, Cleveland. He was an accomplished flautist, and wrote extensively about the instrument, provided a catalogue of literature on the flute, and gathered an important collection of flutes (now in the Library of Congress, Washington, DC). His most important contribution as an acoustician was the development in 1909 of the ‘phonodeik’, which incorporated a diaphragm of thin glass closing the end of a receiving horn; this allowed him to analyse waveforms of various instruments – by means of a thin wire attached to the centre of the diaphragm, which passed over a spindle pulley, the rotation of the spindle (due to movement of the diaphragm) was recorded by light reflected from a mirror affixed to the spindle. He also carried out experiments on organ pipes and trumpets having walls of different thicknesses, although his conclusions about the desirable qualities for the containing walls of an instrument have been challenged by more recent studies. He became an expert on engineering acoustics and was responsible for the design of many concert halls. His 32-element harmonic synthesizer won him a medal from the Franklin Institute....

Article

Murray Campbell and Clive Greated

(b Madison, SD, March 27, 1929). American physicist and acoustician. After studying at Luther College, Iowa (BA 1950), and Iowa State University (MS 1952, PhD 1954), he worked for the Sperry Rand Corporation. He was appointed professor of physics at St Olaf College, Minnesota, in 1957, then at Northern Illinois University in 1971. He has contributed greatly to the understanding of percussion instruments. Particularly noteworthy was his experimental demonstration of Chladni figures showing the vibrational modes of a kettledrum head (1982) and his work on bells (1984). His research with Johan Sundberg and colleagues in Stockholm revealed important features of the formant characteristics of the voice in solo and choral singing. He is best known as co-author of the influential The Physics of Musical Instruments (1991).

‘The Physics of Kettledrums’, Scientific American, no.247 (1982), 172–8 ed.: Acoustics of Bells (Stroudsburg, PA, 1984)...

Article

James F. Bell

revised by Murray Campbell

(b Richwood, OH, June 13, 1868; d Cambridge, MA, Jan 10, 1919). American acoustician. He studied at Ohio State University and Harvard, where he taught physics from 1890; between 1895 and 1919 he laid the foundations of architectural acoustics on the basic principles of engineering design. C.W. Eliot, president of Harvard, prevailed on Sabine to try to correct the serious problem of reverberation in the lecture hall of the Fogg Art Museum, his first acoustical project. At Eliot’s urging he also served as consultant for the Boston Music Hall: his outstanding success there illustrated the effects that could be achieved when acoustical engineering design preceded construction. Sabine’s discovery of the relation among reverberation time, absorbent capacity and the volume of an auditorium was a fundamental and new contribution; he earned a lasting reputation for the scope and perception of his work. It is indeed appropriate that the unit of sound-absorbing power is named the ‘sabine’. His ...

Article

Murray Campbell

(b 1892; d 1979). American engineer and acoustician. He had a distinguished professional career as an electrical engineer, specializing in research into radio wave transmission. In 1957 he retired from the directorship of radio research at Bell Telephone Laboratories. An enthusiastic amateur cellist, Schelleng undertook a programme of research into the acoustics of the violin family in his retirement. The combination of his musical experience and his background in electrical engineering resulted in a novel and extremely fruitful approach to the study of bowed string instruments, in which he drew an analogy between the exchange of vibrational energy between the string and the body of the instrument and the flow of electrical current round a circuit. His seminal paper, ‘The Violin as a Circuit’ (1963), provided the first realistic picture of how the violin functions as a whole, and became the foundation for most subsequent work in this area. Schelling was a pivotal figure in the group of researchers in violin acoustics which adopted the whimsical name Catgut Acoustical Society at his suggestion. He worked closely with Carleen Hutchins on the development of the Violin Octet, a set of new instruments based on the application of scaling theory to the violin. He was elected a fellow of the Acoustical Society of America in ...

Article

Tom Cleveland

(b Normal, IL, Jan 31, 1909; d Los Angeles, Jan 10, 1971). American singer and voice science researcher. He studied English at Taylor University, Upland, IN (AB 1930) and music at Northwestern University, Evanston, IL (BM 1941) and at the American Conservatory, Chicago (MM 1943). After teaching at the Chicago Evangelistic Institute, DePaul University and the American Conservatory, he became a member of the faculty of music at the University of Southern California (1946), chairing its voice department (1950–71). Among the associations to which he belonged are the National Association of Teachers of Singing, which he served in several capacities, including national president. He was awarded an honorary doctorate from Pepperdine University College, Malibu, CA in recognition of his outstanding contributions to singing and the science of singing (1970).

As a singer, Vennard was active in opera, oratorio and solo song; as a teacher of singing, his students, among them Marilyn Horne, achieved worldwide success. His renowned text, ...