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Obituary | Karl Uno Ingard | 1921-2014
Karl Uno Ingard (known gen- erally as K. Uno Ingard), a Fel- low of the Acoustical Society of America and a former recipient of the Society's Biennial Award (1954) and of the Society’s Gold Medal (1998), passed away on August 21, 2014, at the age of 93. He was one of the world’s most eminent acousticians during the second half of the twentieth cen-
tury, and he excelled at theory, experimentation, and teach- ing. He made extensive contributions to physical acoustics, atmospheric acoustics, fluid dynamics, plasma physics, magnetohydrodynamics, and noise control.
Ingard was born in Gothenburg, Sweden, on February 24, 1921, graduated from the Tekniska Gymnasiet in Gothen- burg, entered Chalmers Institute of Technology in 1940, and graduated as an electrical engineer in 1944. Following his graduation, he continued at Chalmers, working toward the degree of Technologie Licentiate.
His principal mentor, Olof Rydbeck, was inclined toward theory, but Ingard was put on experimental projects as well, and his interests broadened to a combination of both experi- ments and theory. Around that time, Per Bruel was setting up an acoustics laboratory at Chalmers, and Ingard worked in his laboratory, initiating his life-long interest in acoustics. It was there that Ingard invented the graphic level recorder, which was later commercially produced by Bruel and Kjaer.
Ingard was attracted to MIT for his doctorate partly because of two books by Philip McCord Morse and partly because, as an aftermath of WWII research activities, MIT had es- tablished a relatively large research laboratory in acous- tics. Although Morse had moved on to interests other than acoustics, Ingard struck up a life-long close acquaintance with Morse, probably initiated by his pointing out to Morse various errors in Vibration and Sound (Morse, 1948). Morse was so impressed that he enlisted Ingard to go through and critique the extensive notes and manuscripts of what was eventually to become the two-volume treatise, Methods of Theoretical Physics (Morse and Feshbach, 1953).
Ingard’s doctoral thesis, “Scattering and Absorption by Acoustics Resonators,” was primarily devoted to experiment and was done under the supervision of Richard H. Bolt. Af-
ter finishing his doctoral work in 1950, Ingard became an as- sistant professor of physics at MIT, where he remained until he retired in 1991 from his positions as professor of physics and of aeronautics/astronautics.
Ingard’s extensive research achievements are extremely var- ied and difficult to summarize in a short account, but many of his numerous papers have been extensively cited through the years and have influenced the research of many others. It is perhaps fair to say that Ingard achieved an insight into engineering acoustics and physics-related acoustics greater than any of his contemporaries.
An undergraduate thesis was required of all physics students at MIT and the intrinsic appeal and breadth of Ingard’s re- search interests, along with the high regard for his teaching, led to his directing a large number of undergraduate theses. Many of the students who wrote bachelor’s theses with In- gard went on to become prominent in acoustics. More than 36 students wrote doctoral dissertations under Ingard’s su- pervision, including several who went on to achieve special eminence in the Acoustical Society: Ira Dyer (President, 1997–87; Gold Medal, 1996), Richard H. Lyon (President, 1993–94; Gold Medal, 2003), and George Maling (Silver Medal in Noise, 1992).
Ingard’s legacy in acoustics is huge. His many papers and books will long continue to be consulted and cited, and those who knew him will long cherish their memories of conver- sations they had with him and of the excellent lectures they heard him give.
The portrait accompanying this account was painted by Doris Ingard, Uno’s wife.
References and Selected Publications by Uno Ingard
Ingard, K. U. (1988). Fundamentals of Waves and Oscillations. Cambridge University Press, New York.
Ingard, K. U., and Dear, T. A. (1985). Measurement of acoustic flow resis- tance. Journal of Sound and Vibration 103, 567-572.
Morse, P. M., (1948). Vibration and Sound. McGraw-Hill, New York. Morse, P. M., and Feshbach, H. M. (1953). Methods of Theoretical Physics, Parts I and II. McGraw-Hill, NY (Reprinted by Cambridge University
Press, NY, for Feshbach Publishing in 2004).
Morse, P. M., and Ingard, K. U. (1987). Theoretical Acoustics. Princeton Uni-
versity Press, Princeton.
Written by:
Allan Pierce, Email: allanpierce@verizon.net Editor in Chief emeritus, ASA
58 | Acoustics Today | Spring 2016