Acoustical Society of America
Gold Medal Award - 1988

Richard K. Cook

RICHARD K. (RK) COOK was born in Chicago, Illinois, on 30 June 1910. After attending local public schools in Chicago, he went on to obtain his B.S. in 1931, his M.S. in 1932, and his Ph.D in 1935, all in the field of Physics. These degrees were all earned from the University of Illinois. He was married to Dorothy Sweet in 1938 until her death in 1984. He has one son, Michael.

His first employment was as an assistant in physics for the University of Illinois (19301935). From there he went to the National Bureau of Standards (NBS) and he spent most of the rest of his professional career there.

From 1935 until 1966, RK worked as a physicist for the NBS serving as the Chief of the Sound Section from 1942 until 1966. Besides his administrative duties, RK contributed extensively to the technical literature on the subjects of microphones, microphone calibration, architectural and room acoustics, reverberation room characterization, piezoelectric properties of crystalline quartz, and eventually in the field of infrasonics. During these years, he published about 30 technical papers to the archival literature as sole author or in collaboration with other members of the Sound Section staff (M. Greenspan, P. Weissler, P. Chrzanowski, R. G. Breckenridge, F. Biagi, R. Berendt, S. Edelman, M. Thompson, J. Wasilik, R. Waterhouse, J. Albrite, R. Shutts, M. Whitlock, E. Corliss, M. Burkhardt, J. Young, W. Koidan, V. Goerke, E. Smith, H. Bowman, A. Bedard, T. Proctor, T. Bartel, and S. Yaniv). His work on developing an absolute microphone calibration procedure based on the notion of reciprocity, formulating the correlation coefficient approach to evaluating reverberation fields, and his improvement of the diffuse field condition in the reverberation method by use of signal modulation and by using moving diffusers are indicative of his creative abilities. During these years, RK found time to be Associate Editor of Sound (196263) and Senior Editor of the Journal of the Washington Academy of Sciences (1955) and also the Editor on Acoustics for the American Institute of Physics Handbook

Between the years 1966 and 1971, RK was Chief of the Geoacoustics Group, part of the National Oceanic and Atmospheric Administration, and concentrated his technical talents on infrasonics. He returned to NBS in 1971 as a Special Assistant on Sound Programs for the Director until his official retirement in 1976. During this period (196676), Cook continued to contribute to the technical literature by publishing about 20 additional journal articles in the fields of infrasonics, sound power measurements, and diffuse sound fields. Since 1976, Cook has acted as a consultant to NBS on acoustical matters.

Over his professional career, Cook found the time to present over 50 talks before various technical societies, 38 of which were given before the Acoustical Society.

In Moe Greenspan's nominating letter, a number of accomplishments are listed as an illustration of RK's vast creative powers. I relate two of these in particular by way of demonstrating his creative vision and incisive understanding of various branches of Acoustics with which he was involved:

$\bullet$ "The connection between microbaroms (natural atmospheric sounds with a period of 4 to 7 seconds) with ocean waves was suggested by Daniels in 1952. He supposed the microbaroms to be sound generated by the undulation of the infinite ocean. In 1962 Cook showed that long train waves cannot radiate sound power, but that a train, which is terminated abruptly, as on a beach, can, so that the sound power seems to come from a line source on the beach." $\bullet$ "The situation is different in the case of Rayleigh waves traveling on the earth's surface, e.g., after an earthquake, as Cook showed in 1965. The vertical component of motion of the earth's surface radiates sound almost vertically. Because there is little attenuation at these infrasonic frequencies and because the air density decreases with altitude, the particle velocity increases markedly with altitude until a shock wave is formed or until the wave passes into the ionosphere. Proof came during the Alaskan earthquake of March 28, 1964. NBS infrasonic stations at Boulder and Washington, D.C. recorded pressures of about 20 dynes/cm$^2$ and with a period of 25 seconds. The corresponding vertical motion of the earth's surface was about 0.5 cm/s (displacement=2 cm). According to the calculations from the theory, a shock consisting of a vertical oscillatory motion of several hundred m/s would occur at 140 km altitude. The expected shock was confirmed by D. H. Baker of NBS Boulder Laboratories. He found from the Doppler shift of radio waves reflected off of the ionosphere that an apparent vertical motion of the ionosphere of several hundred meters was measured about nine minutes after the surface Rayleigh arrived at Boulder station. This delay time was almost exactly equal to the calculated transit time for the sound wave to travel to the ionosphere."

He was active in many acoustic standards committees such as the ISO, ANSI, ASTA, AMA, and IEC, being the co-chairman of ANSI S1 for several years. He was also active on advisory committees to NASA, ESSA (now NOAA), and several Defense Department committees.

RK also held a variety of teaching posts, instructing in Mathematics for the U.S. Department of Agriculture Graduate School between 1941 and 1950 and in various courses in Math, Physics, and Engineering for the NBS Graduate School and Catholic University. He also acted as Adjunct Professor for the EE Department of Brooklyn Polytechnic Institute in 1956 while on sabbatical from NBS and working for Bell Telephone Laboratories.

Dr. Cook has been very active in a number of technical societies and organizations. His service to the Acoustical Society was exceptional. He is a Fellow of the Acoustical Society, was on its Executive Council (194853), and was Vice-President (195455) and President (195758). He also is a Fellow of the Washington Academy of Sciences, acting as Treasurer from 19661971 and was elected President for 197273. He is also a Fellow of the American Physical Society and the American Association for the Advancement of Science.

Dr. Cook's accomplishments span an extraordinary gamut of the subdivisions of acoustics, both as a branch of physics and of engineering, as well as including exceptional service to this and other technical societies, to many standards committees, and to the body politic in general. Many people remember RK's involvement in their own particular fields, but, for all of us, he is truly a Renaissance man of Acoustics.

Thomas Proctor