Page 52 - Fall2021

DAVID M. GREEN
Dave’s Contributions to the ASA, Society, and Acoustics
Dave has been a tireless contributor to his discipline and society. In addition to being an ASA president and Gold Medal recipient, he was, among other things, a former chair of the Psychological and Physiological Technical Committee, an associate editor of The Journal of the Acous- tical Society of America (JASA), and an ASA Biennial and Silver Medal honoree. Dave also served on several com- mittees of the National Academies of Sciences (NAS) and the National Research Council (NRC). Among his many honors, he was elected a NAS member in 1978.
These efforts produced important contributions concern- ing issues confronting society. In 1978, Dave led a team that participated in the “reenactment” of the not fully explained 1963 assassination of President John F. Kennedy in Dallas, Texas. Dave’s team also reviewed the testimony of the 178 witnesses to the Kennedy assassination. The team consisted of Fred Wightman, now retired but then at Northwestern University, and Dennis McFadden, from the University of Texas at Austin, also retired. In Dave’s Congressional testimony (available at bit.ly/3seyRdQ), he reported on witnesses’ observations, on issues related to the possible location of the gunshots, and briefly at the end of his testimony, on the possible number of gunshots. Dave explained how the perception of the acoustics of a bullet fired from a high-powered rifle made it difficult to explain many of the witnesses’ observations. He described his team’s opinion that the location of the gunshots during the reenactment was relatively easy for them to determine for some locations and less so for others. Dave pointed out that the team knew that gunshots would be fired and were experts in perceiving sounds, including their source locations, whereas the gunshots would have been a sur- prise to the witnesses who were unlikely to have been skilled observers in perceiving sound. He also indicated that there was no sufficient scientific literature to address issues regarding the number of gunshots, but echoes and the acoustics of high-powered rifle shots probably led to some reports of multiple gunshots.
Then in 1994, Dave chaired a NRC committee deal- ing with issues related to acoustic thermometry of ocean climate (ATOC) and marine wildlife (see nap.edu/read/4557/chapter/1). The issues, as many ASA members might remember, were that the ATOC proj- ect would have produced high-intensity, low-frequency
underwater sounds so that acoustic changes over long dis- tances might provide estimates of global warming of a large area of the earth’s surface (e.g., a lot of the Pacific Ocean); however, marine mammals (and fishes) are sensitive to these same sounds. The committee noted that not enough was known about marine mammal and fish auditory pro- cessing to adequately address the extent to which ATOC signals might adversely affect marine animals. The NRC committee made recommendations about what research might be undertaken and how regulatory requirements could be changed to assist in getting this research done.
Dave’s Students, Postdocs,
and Colleagues
Many who attended Greenfest and probably more than 60 others have studied and conducted research with Dave in his labs as students or postdocs or while on a sabbatical or another form of leave. These researchers have, in turn, passed on lessons learned from Dave to their students, postdocs, and colleagues. As John Swets pointed out in the Encomium for Dave’s ASA Gold Medal in 1994: “Dave most visibly took on this unusu- ally generous interest in the beginner’s growth and recognition. He regards them all as having their stories to tell — and after a few years of his tutelage they really do” (acousticstoday.org/david-green-gold-medal-1994).
Dave and Signal Detection Theory
Dave’s pioneering work on the SDT is contained in the highly cited book by Dave and Swets (1966; hereafter
Figure 3. Dave Green (left) and John Swets (right) at Bolt, Beranek, and Newman in 1965, a year before Green and Swets (1966) was published. Thanks to Chris Conroy for providing this picture.
52 Acoustics Today • Fall 2021