Acoustical Society of America
Gold Medal Award - 1997

Karl Uno Ingard

Turn back the clock to June 26, 1954. 1954 was the year that the Acoustical Society of America celebrated its 25th anniversary, and the highlight of that year was the 25th Anniversary Celebration Banquet held on June 26 at the Hotel Statler in New York. It took three sets of a two-tiered dias to hold the distinguished guests of the acoustics world, many in black ties and white dinner jackets.

There were many speeches and awards given on that historic evening, but, for the present purpose, only one matters. All past recipients of what was then called the Biennial Award stood as ASA President Hallowell Davis announced the name of the 1954 winner, and he called upon Dick Bolt to give the reasons why the Society chose to honor Uno Ingard.

Dick, with what was reported to be a ``suave and polished air,'‘ proceeded to give an entertaining amount of Uno's "life and pursuits" in his native country, Sweden. Of Uno's ability as a track star, he said that "the Swedish newspapers of the early ‘40s carried many a headline on Ingard as ‘The Youthful Flash!'" Of Uno's scientific skills, he pointed out that "One measure of scientific contribution is the publication rate. I think his publication rate is perhaps unparalleled in the 25 years of our Society." Dick went on to describe the breadth of Uno's scientific work—his studies of resonators, his development of the graphic level recorder, his contributions to sound propagation outdoors, and other achievements.

Although Dick identified Uno as "an inspiring professor," nowhere in the encomium is the word "teach" mentioned. However, in his short remarks after receiving the Biennial Award, Uno used the word twice as he thanked those who taught him. Today, 43 years later, Uno is again being honored by the Acoustical Society of America. It is no accident that his citation reads, in part, ...the teaching of physical acoustics and noise control. I view myself as only a representative of the many students that have benefitted greatly by Uno's insight into solving problems, doing research, and communicating the results to others.

When I returned to the Electrical Engineering Department at the Massachusetts Institute of Technology (MIT) in the spring of 1957 after earlier studies in acoustics at MIT and two years in the U.S. Army, I was offered a choice between speech and noise at the MIT Acoustics Laboratory. I chose noise with Ingard and I have never regretted it. Uno soon convinced me to switch into the Ph.D. program in his department, physics. The switch was not that easy, but with his guidance I completed a thesis related to wave propagation in inhomogeneous media and embarked on what has proved to be a very satisfying career in noise control.

I am sure that Uno's other students have similar stories to tell. During his career at MIT, both in the Physics Department and in the Aeronautics Department, he supervised about 150 theses; about 50 of these were doctoral theses. I can only mention a few of his students that I have had the pleasure of knowing over the years. These include Ira Dyer, Dick Lyon, the later Peter Franken, David Pridmore-Brown, Bert Willke, George Lamb, Ken Gentle, Wally Dean, Bob Katyl, Jim Witting, Paul Fleury, Anthony Galaitsis, George Succi, and Bill Patrick.

Three of his students, Ira Dyer, Emmanuel Papadakis, and Peter Rogers, were awarded the Biennial Award (now the R. Bruce Lindsay Award) of the Society, and one, Ira Dryer, was awarded the Society's Gold Medal. Another student, Dick Lyon, was awarded the Rayleigh Medal by the Institute of Acoustics in the United Kingdom, an award that Uno himself received in 1981. I was honored to receive the Society's Silver Medal in Noise in 1992, something that never would have happened without the benefit of my years with Uno Ingard.

Uno has been a teacher for more than 50 years. He began teaching in 1945, before he became director of the Acoustics Laboratory at the Chalmers Institute of Technology in 1946. He was on leave from Chalmers when he completed his Ph.D. at MIT under Philip Morse in 1950, and he joined the physics department shortly thereafter. He taught undergraduate courses in theoretical physics, as well as a course on vibration and sound based upon the well-known text by Morse. Other courses included fluid and plasma physics, and several of the theses that he supervised over the years were related to instabilities and waves in weakly ionized gases. His contributions to propagation and instabilities in plasmas, and to laser scattering, are widely recognized in the physics community.

In 1971, he began teaching a graduate course on noise control engineering in the Aeronautics Department—the first, or at least one of the first, courses was devoted specifically to that subject. His research interests included aeroacoustics, sound propagation in ducts, and structural acoustics.

Uno has also been an educator for scientists working in industry; his consulting activities have resulted in important contributions to duct acoustics, the theory of fan noise in ducts, jet engine noise, jet engine silencers, sound absorptive materials and sound absorptive structures.

He has given us a wealth of information through his papers and his books, one example being Theoretical Acoustics written with Philip Morse.

Uno retired from MIT in 1991, but he continues to be very active in research, writing, and consulting.

All of the awards that Uno has received over the years are too numerous to list here. However, in addition to the Rayleigh Medal mentioned above, they include membership in the National Academy of Engineering, the John Ericsson Medal of the American Society of Swedish Engineers, an honorary doctorate from his university in Sweden—the Chalmers Institute of Technology, membership in the Royal Scientific Society in Gothenburg, Sweden, the Education Award of the Institute of Noise Control Engineering, and the Per Bruel Gold Medal of the American Society of Mechanical Engineers.

I am sure that I speak for all of his students when I express my thanks for the opportunity to have studied with Uno Ingard. His insight into physical problems, and his willingness to engage his students in dialogues that broaden their understanding of physics, acoustics, and noise control is something for which all of us will be forever grateful.

George Maling