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The Silver Medal is presented to individuals, without age limitation, for contributions to the advancement of science, engineering, or human welfare through the application of acoustic principles, or through research accomplishment in acoustics.
CITATION FOR NEAL F. VIEMEISTER PITTSBURGH NEAL VIEMEISTER was born on January 14, 1944 in Brooklyn, NY and grew up on Long Island. Among his fondest childhood memories is of a trip with his father to Ebbets Field where a camera caught him with his heroes of the Brooklyn Dodgers, Gil Hodges, Duke Snider, and Peewee Reese. In high school, Neal played the saxophone, fell in love with mathematics and developed a lifelong interest in music and science. When the time came to pick a college, he succumbed to the traveling itch that is still with him, and opted for a place far from New York, Grinnell College in Iowa. Neal spoke so highly of the quality of his educational experience in Iowa that, years later, Katie Viemeister, the daughter of Neal and his first wife, Linda, also decided to attend Grinnell.
While an undergraduate in Physics, Neal’s fascination with music and musical instruments led him to discover “Chladni plates,” a 160-year-old method for observing the acoustic modes of flat surfaces through distributions of sand on vibrating plates. This connected him to the Journal of the Acoustical Society of America (JASA) and led to a student membership in the Society in 1965. Thus began an extraordinary bond with the Society that has produced many important papers, Associate Editorship of the Journal, and a role in the leadership of the technical committee on Psychological and Physiological Acoustics as well as the Society as a whole. With graduation looming on his horizon, Neal did an historical analysis of papers published in JASA and concluded that the best place for graduate training would be the Psychoacoustics Laboratory at Harvard. However, one of his professors told him of a revolutionary new approach to the study of hearing, Signal-Detection (SDT), evolving in a few pioneering laboratories in Michigan and Indiana. He invited Neal to join a group of Grinnell seniors on a visit to Indiana University where young Viemeister could meet with Professor James P. Egan in Psychology. By the end of a private two-hour discussion that featured one of Jim Egan’s enthusiastic lectures on SDT, no other graduate program would do.
With Egan away on a year’s sabbatical, the first year of graduate school was spent studying how rats learn. Once, Egan returned, Neal devoted his energy to his heart’s desire, psychoacoustics. Indiana was a great place to study perception, with a faculty in hearing and vision that included Egan, W. van Bergeijk, R. DeValois, L. Guth, C. Mueller, W. Neff and, especially, Don Robinson. There was also an impressive group of students and post docs; indeed, Neal credits much of his later success to participation in the ad hoc seminars that took place in the sainted halls of Nick’s Bar. When Egan moved to the University of Washington, Neal accompanied him and participated in the establishment of a new lab while completing his dissertation. A Ph.D. from Indiana in 1970 was followed by a year as a visiting Assistant Professor in Minnesota. The now Dr. Viemeister then completed his formal education as a post-doctoral fellow with another giant of the Acoustical Society, Dave Green, at the University of California in San Diego.
In 1972, Neal returned to Minnesota as a regular member of the faculty in Psychology, where he has remained. He and his wife, Virginia Kirby, now live on Bald Eagle Lake with their much loved Labrador, Zoe, the family sailboat from Long Island, his treasured Kipschorn speakers and an extensive collection of CDs. His love of music has never flagged and many morning, while his is working out on the Nordic Track, his neighbors can hear the “Ride of the Valkyries” wafting over the still waters of this lovely Minnesota lake.
Neal’s career is distinguished by his ability to combine inventive experimental techniques with incisive mathematical analysis for modeling one of the oldest and most important topics in the field; namely, how the auditory system encodes stimulus intensity. An history problem was how to reconcile the fact the listeners can discriminate small changes in sound level over a dynamic ranger of 120 dB while individual neurons in the auditory nerve showed a limited dynamic range of only 40 dB. Traditional wisdom had opted for a “staggered threshold” hypothesis with separate neurons covering a different portion of the range, but that possibility was brought into question, based on data from N. Kiang, which suggested that all of these neurons had essentially the same threshold. Consequently, an alternative view arose arguing for intensity discrimination at high levels based on spreading excitation in the cochlea to neurons not normally triggered by the signal’s frequency. In a direct test of this idea, Neal used notch-filtered noise to prevent off-frequency listening and found that normal discrimination continued over the entire dynamic range. Based on an elegant application of SDT, he then showed that relatively few auditory neurons with high thresholds could account for discrimination at high levels, a theory that fits beautifully with physiological experiments from C. Liberman that describe a small population of high-threshold fibers that previously had been overlooked.
Another classical problem in intensity coding has been the seeming contradiction between various measures of temporal integration. Under some circumstances, the auditory system seems to act like a simple integrator with a time-constant of 50-300 milliseconds (ms). Yet, listeners easily detect temporal gaps in a on-going sound of less than 5 ms. In a study that compared the detection of a pair of short pulses separated either by a short, silent gap or by a gap filled with noise, Neal and his students found that the noise did not reduce detection. Based on a SDT analysis, they showed that it was unnecessary to assume that signal detection is based on 300 ms integrator, arguing instead for statistical use of multiple observations with integration time of just a few milliseconds.
Among Neal’s many contributions, perhaps the best know has been to or understanding of the perception of complex, wide-band stimuli such as speech and music, especially sensitivity to extract small temporal changes encoded in the stimulus envelope. For this, he concentrated on discrimination of amplitude-modulation (AM), adopting a linear-systems approach similar to that applied to the study of spatial vision. His development of these temporal-modulation transfer functions has had far-reaching effects, fostering a strong interest in the study of AM now found in psychological and physiological acoustic laboratories around the world.
In addition to his research, Professor Viemeister has made an important contribution through the nurturing and training of future scientists. A list of his graduate students and post-doctoral fellows include S. Bacon, E. Burns, B Edwards, D. Fantini, C. Plack, M. Rickert, M. Stellmack, E. Stickland, G. Wakefield, G. Widin, and M. Wojtczak. Students have learned from his example to pay deep attention to experimental detail, to clarify an issue through mathematical modeling and to maintain an abiding curiosity and true joy of discovery. His papers are models of clarity, and students and collaborative colleagues alike treasure him as a suburb editor who returns a manuscript with detailed comments and useful suggestions for the authors. One previous editor has said, “Viemeister’s reviews could serve as examples to young scientists of how the peer review process should work.”
In summary, Neal Viemeister is know world-wide for his contributions to the knowledge of the functioning of the auditory system. Through his writing, editing, reviewing and involvement with students and collaborators, he has helped shape the modern landscape of psychoacoustics, leaving a permanent mark on every topic he has touched. He has been an excellent citizen of the Society and no one is more deserving of the Silver Medal in Psychological and Physiological Acoustics.
ERVIN R. HAFTER ©2002 Acoustical Society of America.
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5 JUNE 2002