Tempe, Arizona - We learn the basics of hearing sound waves, ear parts, and the effects of pitch and volume sometime around third grade, but there are still mysteries to unravel, including how we process where sounds are located, especially if there are a lot of different sounds at one time, or how we handle sounds that are moving.
William Yost has spent almost 40 years trying to solve those mysteries.
In recognition of this work as well as his service in the hearing and acoustics fields, Yost, a research professor of speech and hearing science in Arizona State University's College of Health Solutions, received the Acoustical Society of America’s (ASA) Gold Medal, the society’s highest honor.
Yost was among the first sound researchers in the late 1980s to describe the brain’s role in perceiving sound when the ear is confronted with many different sounds at the same time. Before then, sound study and hearing science focused mostly on the basic attributes of sound, such as pitch, loudness and sound quality, but Yost’s research showed that it is actually the brain and ear working together which determines how people hear in complex environments. Termed “auditory scene analysis,” this discovery has had important implications for how cochlear implant patients and hearing aid users process sound.
Since joining ASU in 2007, Yost has continued to build on this research with ongoing study of what is known as “sound source localization,” or how a person locates sound if both the sound and the listener are moving.
“Since being at ASU, I have realized that in the real world where sound sources and listeners move, the brain has even more challenges in determining sound source location,” Yost said. “How does the brain know where a sound source is if it moves as compared to when it and/or the listener moves? We can’t answer that question yet, but we’re getting close to an answer.”
Yost’s research embodies ASU’s spirit of innovation, said Michael Dorman, professor emeritus of speech and hearing science, and a colleague of Yost’s who collaborated with him on more than a dozen publications involving sound source localization and cochlear implants.
“Bill’s basic science work on spatial hearing fits perfectly with ASU’s emphasis on translational research," Dorman said. "Many companies, including those working in virtual reality, have come to him for advice on how we locate sounds both in space and moving through space.”
Google and Apple have used some of Yost’s work in developing their sound-related products, and Oculus VR, manufacturer of the virtual reality system Rift, is funding Yost’s current research on how to better process sound for use in virtual reality contexts. In addition to technology applications, his research has also informed policies on the protection of marine mammals.
While both Oculus and the National Institute of Health fund Yost’s current research, his work has received continuous funding since 1968 from many agencies including the Air Force Office of Scientific Research, the Environmental Protection Agency and several private foundations and industries.
“Most of us have gaps in our funding,” said Nancy Scherer, professor of speech and hearing science and current program chair. “The fact that Dr. Yost has had continuous funding speaks volumes about how solid his research is.”
Teaching and service are other important components of Yost’s long career. His textbook, "Fundamentals of Hearing: An Introduction," first published in 1977 and now in its fifth edition, is considered a seminal text. He has been a member of almost every professional and scientific organization associated with hearing and sound, including the American Auditory Society and the American Speech Hearing and Language Association, and he served as president of both the Acoustical Society of America and the Association for Research in Otolaryngology.
Yost received the Gold Medal at the ASA’s 175th meeting in May.