Microphone

In this interview organized through the Acoustical Society of America, German inventor and scientist Gerhard Sessler reflects on his life and career in acoustics. Sessler begins by recalling his childhood in Germany and his high school math teacher who inspired him to study physics. He describes the beginning of his undergraduate studies at Freiburg University before transferring to the University of Munich, where he took classes from physicists such as Arnold Sommerfeld. Sessler recalls moving to the University of Göttingen for his graduate studies, where he was introduced to the field of acoustics by Erwin Meyer. He describes his master’s thesis on sound propagation in rarefied gases. Sessler then explains the opportunity that led him to Bell Labs to work with Manfred Schroeder, where his projects included work on transducers, electrets, sound propagation in plasma, and architectural acoustics. He discusses his collaboration with Jim West on the development of electret microphones, first using Mylar films and then transitioning to Teflon. Sessler recalls his decision to return to both academia and Germany by accepting a position at Darmstadt University. There, he continued his work on electroacoustics, materials research, and room acoustics, and he discusses his work on developing silicon microphones. Toward the end of the interview, Sessler recounts his time as chairman of the first German acoustics association, DAGA, and then his role as founding member of the German Acoustics Society, DEGA. He also reflects on the honor of being elected to the National Inventors Hall of Fame in 1999, as well as receiving the Benjamin Franklin Medal in Electrical Engineering.

In this interview organized through the Acoustical Society of America, Per Brüel discusses his life and career, focusing especially on his introduction to the field of acoustical instrumentation and his work in industry. It also discusses his association with ASA and other national acoustical societies. Brüel recalls his upbringing in Jutland, education at what is now called the Technical University of Denmark, experiences during World War II, early R&D work in Sweden, and his relationship with figures such as P. O. Pedersen and Viggo Kjær. He also discusses his work on architectural acoustics and the origins and successes of such Brüel & Kjær products as the constant percentage analyzer, level recorder, and condenser microphone, as well as his criticisms of the A-weighting curve used in noise measurement. He reflects on Brüel & Kjær management issues, including his division of responsibilities with Kjær, how they made decisions jointly, relations with universities, advertising, and the strategic decisions leading up to the sale of the company in 1992. The interview concludes with discussions of Brüel’s interest in cars and flying, his family, and his activities following the sale of Brüel & Kjær.

In this interview with former Acoustical Society of America president Mike Stinson, the discussion begins with Stinson’s experiences as a member of the society and recollections of his work with Shyam Khanna. The interview then shifts to Stinson’s youth near Vancouver, British Columbia, including his undergraduate education and master’s degree work in physics at Simon Fraser University. Stinson then recounts work in the sawmill industry and his decision to pursue a doctorate at Queen’s University in Kingston, Ontario, involving research on the electrical and thermal conduction properties of metals at low temperatures. Stinson discusses his career at the National Research Council of Canada, where he moved into acoustics, working with researchers such as Gilles Daigle, Dave Havelock, Edgar Shaw, and Tony Embleton, and technicians such as Allen Hellard and Marina Vaillancourt.  He also recounts particular projects, such as work on the acoustics of Blackberry devices and the effects of atmospheric turbulence on sound, as well as the NRC’s decision to discontinue his group and his establishment of the company MG Acoustics with Daigle, who is also the interviewer.

In this interview organized through the Acoustical Society of America, the discussion begins with West’s experiences as a member of the society before moving into his family background and youth in Virginia, education at Hampton Institute and Temple University, and military service in the Korean War. West describes his employment with Bell Labs and his work on the electret microphone, for which he and Gerhard Sessler would be inducted into the National Inventors Hall of Fame. He also discusses his experiences as a Black member of the technical staff at Bell Labs, the importance of being in a research environment with people of similar backgrounds, and the creation and successes of the Association of Black Laboratory Employees (ABLE). West further describes his work in the acoustics of concert halls and hospitals and on the design of devices for taking medical measurements. The interview concludes with West highlighting his work during his presidency of ASA to expand its reach in Latin America and to attract and support people of Hispanic origin to acoustics.

Studies in Europe, 1912; graduate study under Robert A. Millikan at University of Chicago; employment with Western Electric Co. and Bell Labs, 1917-1956; brief time doing experimental work on the "carbon microphone" and long distance sound detectors; review articles on contemporary advances in physics, 1920s-1930s; description of early meetings of American Physical Society (APS); 1933 visit to European centers for physical research; work on the relationship between commercial and basic research in physics. Organization and growth of APS, his terms as Secretary, 1941-1956, during which he introduced "invited papers" to major meetings; problems within APS and within the area of physics in general; his role in fostering international cooperation in physics. Outside interests. Also prominently mentioned are: Hans Albrecht Bethe, William Lawrence Bragg, Percy Williams Bridgman, J. J. Carty, Arthur Holly Compton, Clinton Joseph Davisson, Arthur Jeffrey Dempster, Enrico Fermi, James Brown Fisk, Harvey Fletcher, James Franck, Lester Halbert Germer, H. E. Ives, Frank Jewett, Arthur Lunn, Albert Abraham Michelson, George Braxton Pegram, Isidor Isaac Rabi, Frances Orr Severinghaus, William Francis Gray Swann, John Hasbrouck Van Vleck, Harold Worthington Webb; American Institute of Physics, United States National Bureau of Standards, and University of Chicago.

Studies in Europe, 1912; graduate study under Robert A. Millikan at University of Chicago; employment with Western Electric Co. and Bell Labs, 1917-1956; brief time doing experimental work on the "carbon microphone" and long distance sound detectors; review articles on contemporary advances in physics, 1920s-1930s; description of early meetings of American Physical Society (APS); 1933 visit to European centers for physical research; work on the relationship between commercial and basic research in physics. Organization and growth of APS, his terms as Secretary, 1941-1956, during which he introduced "invited papers" to major meetings; problems within APS and within the area of physics in general; his role in fostering international cooperation in physics. Outside interests. Also prominently mentioned are: Hans Albrecht Bethe, William Lawrence Bragg, Percy Williams Bridgman, J. J. Carty, Arthur Holly Compton, Clinton Joseph Davisson, Arthur Jeffrey Dempster, Enrico Fermi, James Brown Fisk, Harvey Fletcher, James Franck, Lester Halbert Germer, H. E. Ives, Frank Jewett, Arthur Lunn, Albert Abraham Michelson, George Braxton Pegram, Isidor Isaac Rabi, Frances Orr Severinghaus, William Francis Gray Swann, John Hasbrouck Van Vleck, Harold Worthington Webb; American Institute of Physics, United States National Bureau of Standards, and University of Chicago.