Acoustical Society of America Gold Medal

Vern Oliver Knudsen (1893-1974), a founding member and third president of the Acoustical Society of America, had a long and distinguished career as a teacher, acoustician, physicist, academic administrator, and consultant. His career in acoustics began at the Bell Telephone Laboratories, and continued at UCLA, where he was head of the Physics Department, vice-chancellor, and chancellor. Knudsen was born in Provo, Utah, on 27 December 1893. He entered Brigham Young University in 1911 and came under the influence of Professor Harvey Fletcher, whom he credits with steering him toward physics rather than mathematics or engineering as he originally planned. In his senior year he assisted Fletcher in his research on Brownian motion. Following his graduation in 1911, he served as a Mormon missionary and as acting head of the Northern States Mission in Chicago. During World War I he investigated parasitic earth currents using the western segment of the St. Pierre cable, which had broken in mid-Atlantic. The 1700-mile segment terminated at the Chatham, Massachusetts cable station. The purpose of the measurements was to determine what could be done to speed up cable telegraph transmission of messages across the Atlantic during the war to “carry the wording communications between Woodrow Wilson and Lloyd George.” He found that interfering earth currents with frequencies between about 5 to 15 Hz were largely attributable to fluctuations in the Earth’s magnetic field. Knudsen joined Harvey Fletcher at the Bell Telephone Laboratories (then Western Electric) in 1918, where he worked on the development of amplifiers and oscillators, increasing his knowledge of the new technology of vacuum tubes which Fletcher and his colleagues were using in their studies on hearing. In 1919 he began his graduate studies at the University of Chicago as a student of A. A. Michelson. As a suitable subject for his doctoral dissertation, R. A. Millikan proposed a study of the contribution of electrons to the specific heat of metals, a problem previously investigated by Debye, Nernst, and Einstein, but not solved. Recognizing the probable long duration of such a study, Knudsen sought advice from Dean Henry Gordon Gale during a period when Millikan was in Europe. Dean Gale proposed a study of acoustics, which would be well advanced by the time Millikan returned. Knudsen worked rapidly to measure the sensibility of the ear to small differences of intensity and frequency, using vacuum tube techniques acquired from the Western Electric Research Laboratories. When Millikan returned, he approved the study and introduced Knudsen to George Shambaugh, one of the foremost otologists in the U. S. Subsequent association with Shambaugh resulted in studies on the sensibility of pathological ears to small differences in loudness and pitch and to diplacusis. Knudsen received the Ph.D. in physics magna cum laude in 1922. He confounded both colleagues and teachers by turning down offers from the University of Chicago and the Bell Telephone Laboratories to accept the position of Instructor at the newly-formed University of California Southern Branch, later to become UCLA. The Southern Branch occupied a small campus near what is now central Los Angeles; all the buildings together were smaller than Knudsen Hall on the UCLA campus today. Knudsen overcame the lack of facilities by reaching out to his surroundings: he studied the architectural acoustics of local auditoriums and classrooms, most of which were acoustically bad. Volume 14, Number 1 Winter 2004