Harry F. Olson

Acoustical Society of America

Gold Medal Award


Harry F. Olson

THE HALF-CENTURY roughly spanning the years between 1925 and 1975 was the era of a generation of giants in the field of acoustics. Fourteen of these outstanding persons have already received special recognition in the form of the Gold Medal Award of the Acoustical Society of America. The Society is now proud to bestow his honor on yet another of the pioneers of that era, Dr. Harry F. Olson.

Harry F. Olson was born in Mt. Pleasant, Iowa on 28 December 1901. He attended the University of Iowa in Iowa City, receiving from that institution the B.E. degree in 1924, the M.S. degree in 1925, and the Ph.D. degree in physics in 1928. On the basis of subsequent work he was awarded the Professional degree of E.E. in 1932. He was also the recipient of an honorary D.Sc. degree from Iowa Wesleyan College, Mt. Pleasant, Iowa. Dr. Olson's Ph.D. dissertation was based on experimental studies of the resonance radiation of atoms and of the reflection of atoms from crystals. However, his contacts as a student with Dean Carl Seashore, a pioneer in the science of musical sounds, and with Professor G. W. Stewart, inventor of the acoustical wave filter, led him into the field of acoustics, where his interdisciplinary training in engineering and physics proved to be of great value.

Dr. Olson's professional career has been closely linked with RCA, first with the Photophone Division of the Radio Corporation of America in New York City, then with the RCA Victor Division in Camden, New Jersey. In the fall of 1942 his Acoustical Research laboratory was one of the first groups to move into the newly constructed RCA Laboratories in Princeton, New Jersey. This new facility included, in addition to well-equipped laboratory bays, an ideal listening room, a reverberation chamber and, at that time, the world's largest and most effective anechoic chamber, all constructed according to Dr. Olson's design and under his supervision. During the greater part of his career he was Director of Acoustic Research in RCA, being elevated to Staff Vice President in 1967.

The interests of RCA's Photophone Division was coupled to the motion-picture industry which, in the 1930's, was struggling with the problems of producing "talking pictures." Improved microphones developed by Dr. Olson were immediately accepted for use on motion-picture sound stages. The omnidirectional pressure microphones were supplanted by Dr. Olson's bi-directional velocity microphones and by his unidirectional cardioid microphones. Over the years the cardioid microphone was continued to be the universal directional microphone. Subsequent years saw his development of higher-order-gradient microphones, ultra-directional microphones, noise-cancelling microphones, miniature and unobtrusive microphones, etc., etc., all of which found commercial and/or military applications. These developments were paralleled with comparable developments in loud-speakers, the result being loudspeakers for almost every conceivable sound-reproduction application. His LC series of coaxial loudspeakers, first teaching commercial production in the 1950's, are still prized by audiophiles seeking the best in linearity and uniformity of response.

During the early years of his career Dr. Olson found time to elucidate and formalize the fundamental mechanisms in acoustical and electro-mechanical devices. This work formed the basis for his books, Acoustical Engineering and Dynamical Analogies, which have long been standard reference tests throughout the world, going through several editions and being translated into Russian and Japanese. Books published in later years are Musical Engineering; Music, Physics and Engineering; and Modern Sound Reproduction. In addition, he has published more than 130 scientific papers. He holds more than 100 U.S. Patents on acoustical devices and systems. During the 1940–1942 academic years he was a lecturer in acoustical engineering at Columbia University in New York City.

Commencing in 1940 and continuing through the years of World War II, Dr. Olson and his laboratory team concentrated on military projects. These included some work on voice communications, transducers, particularly for use in noisy environments. But the bulk of the effort related to underwater sound and antisubmarine warfare. Significant improvements were made in sonar transducers, and underwater transducers operating at frequencies as high as 60 MHz were developed. Other projects included submarine quieting and the development of an acoustic proximity fuse for depth charges.

The conversion back to civilian projects following the war was not difficult since many ideas were waiting to be explored. In RCA's Acoustic Research Laboratory there was a continuing interest both in audio equipment for broadcast and recording studios and in sound-reproduction systems for mass consumer products. In following this latter interest one of Dr. Olson's first post-war projects was his now-classic experiment to determine the preferred audio bandwidth for reproduced sound. Earlier published work by various investigators indicated that the majority of listeners preferred a high-frequency cutoff of about 5000 Hz when listening to music reproduced through amplifiers and loudspeakers. Dr. Olson suspected that this unexpected result might be an artifact related to the reproducing systems employed. Accordingly, he set up a listening room in which groups of listeners could hear music played by a small orchestra behind a screen in the same room. The screen consisted of an acoustic low-pass filter with a cutoff frequency of 5000 Hz. The filter, concealed behind an acoustically transparent but visually opaque curtain, could be opened and closed, allowing the listeners to choose between full-bandwidth and restricted-bandwidth sound. Hundreds of listeners from all walks of life made the test and the result was an overwhelming vote in favor of wide-range sound. The tests were repeated with the live orchestra being replaced by a sound-reproduction system with loudspeakers in the listening room. As long as the reproducing system was free of distortion the same listener preference was found. When small amounts of nonlinear distortion were introduced the preference moved toward restricting the high-frequency bandwidth. This demonstration of the importance of quality in audio systems marked the birth of the audio-electronics hi-fi industry, and the contest among manufacturers to achieve more-nearly perfect specifications for their products continues to this day.

Another early post-war project was the development by Dr. Olson and Herbert Belar of the RCA Electronic Music Synthesizer. This work antedated the transistor as well as all of the computer technology now so commonplace. Using primitive digital-control techniques, as well as analog techniques, all implemented by means of vacuum tubes and relays, the Synthesize was capable of producing any audio signal that could be conceived and specified by the operator. The Synthesizer was used by composers at the RCA Laboratories in Princeton and at the RCA Records Division in New York to compose a number of musical selections. Some of these were issued on an RCA 45 rpm album that is now a collector's item. Shortly thereafter the Synthesizer was moved to the Columbia–Princeton Music Center in New York City where it is still functional. A second model which remained at the Laboratories for a number of years now resides at the Smithsonian Institute in Washington, D.C. More recently the Synthesizer in New York was used by composer Charles Wuorinen to produce his 1970 Pulitzer-Prize-winning "Times Encomium" record. The record was released by None Such Records as Stereo H-71125.

Many of us remember the interest that was generated following the disclosure and demonstration in the United States of magnetic recorders developed by the Germans during the war. Before long a number of American companies, including RCA, undertook the design and production of audio tape recorders. Early analyses and experimental results in audio tape recording at the RCA Laboratories indicated that if breakthroughs in tape quality and in recording heads could be made it should be possible to record television signals on this new medium. The possibilities were so promising that in the early 1950's Dr. Olson was authorized to organize a team in his laboratory to develop a videotape recorder for TV broadcast use. The outcome was a series of full-scale demonstrations in 1954 at the RCA Laboratories in Princeton of the magnetic-tape recording and reproduction of both black-and-white and color TV programs. In these successful demonstrations the luminance and each of the three primary-color signals had its own track on the tape, with the audio recorded on a fifth track. Two more years of diligent effort were required to modify the recording system to meet the stringent requirements of the NTSC specifications for composite color signals. When this was accomplished, the system was moved from Princeton to the NBC studios in New York City to make possible, in May of 1956, the world's first broadcast of tape-recorded color TV signals through the complete chain of a broadcast station. The program was transmitted via microwave link to receivers at the 3M Company in Minneapolis, Minnesota, this site chosen because of the collaboration of the 3M Company in providing the special tape needed for this new technology.

Subsequently, a project in tape-coating technology was initiated in Dr. Olson's laboratory. In due course, the coating equipment and techniques developed in the Princeton laboratory were transferred in toto to Indianapolis where they were used in the commercial production of tapes by RCA's newly-created Magnetic Products Division.

For these achievements as well as for others too numerous to include here, Dr. Olson has received recognition from many sources. He was elected to the National Academy of Sciences in 1959. He is a member of Tau Beta Pi, Sigma Xi, and the American Society of Swedish Engineers. He is a Fellow of the American Physical Society, the Society of Motion Picture and Television Engineers, the Institute of Electrical and Electronic Engineers, and the Acoustical Society of America. He is an Honorary Member, a founder, and a past president of the Audio Engineering Society. In the Acoustical Society of America he served as Associate Editor of the Journal for 30 years, and was on the Executive Council from 1937 to 1940. He also served as Vice President 1942–1944, President Elect 1951–1952, and President 1953–1954. He was awarded the first Silver Medal in Engineering Acoustics of the Acoustical Society of America in 1974.

Other recognition has come in the form of the Modern Pioneer Award of the National Association of Manufacturers (1940, the John H. Potts Medal of the Audio Engineering Society (1952), the Samuel L. Warner Medal of the Society of Motion Picture and Television Engineers (1955), the John Scott Medal of the City of Philadelphia (1956), the Achievement Award of the IRE Professional Group on Audio (1956), the John Ericsson Medal of the American Society of Swedish Engineers (1963), the Emile Berliner Award of the Audio Engineering Society (1965), and the Institute of Electrical and Electronic Engineers' Mervin J. Kelly Medal (1967), Consumer Electronics Award (1969), and Lammé Medal (1970).

Dr. Olson married his wife, the former Lorene Johnson, in 1935. Throughout his years at the RCA Laboratories Lorene's oil paintings were prominent and attractive features on the walls of Dr. Olson's office. Following his retirement in 1967 Dr. Olson was retained by RCA as a consultant for several years. The Olson's reside on Palmer Square in Princeton. His enduring interest in acoustics and audio is manifested by the continued writing and publishing of technical papers in the field to which he has contributed so much in the past.

J. Guy Woodward