Differentiating Sound and Noise: Dr. Douglas Chabries
How does a submariner know if that large object ahead is another submarine, or a whale? By using a sonar system built on the work of one of our founders, Dr. Douglas M. Chabries. He built a distinguished career around a lifelong interest in sounds and images, how they are perceived, recognized, and differentiated by human beings and by technology. He even developed a mathematical model of human hearing. In his long career, he has been awarded 14 U.S. patents and published approximately 70 articles in the academic literature.
After receiving a bachelor’s degree in Electrical Engineering (E.E.) from the University of Utah, a master’s degree in E.E. from the California Institute of Technology, and a Ph.D. from Brown University, Dr. Chabries went to work as a civilian scientist for the U.S. Navy. For 12 years, he conducted research and directed research groups at the Naval Undersea Center in Point Loma San Diego. His specialty was sound recognition; he designed acoustic sonar detection systems.
The algorithms Dr. Chabries developed for this work allows Navy surface ships and submarines to process and identify underwater sounds. This enables ships to differentiate friend from foe, and separate natural sounds, like a school of fish, from man-made ones, like another ship. Much later in his career, his understanding of sound recognition algorithms would play a key role in the development of the digital hearing aid.
After leaving the Naval Undersea Center in 1978, he went on to teach and do research at Brigham Young University in Utah. Once outside the classified world of the military, he gained recognition as a researcher and professor. He eventually became Dean of the Fulton College of Engineering and Technology, winning many awards for science, technology, and teaching excellence.
Dr. Chabries’ research and academic focus at BYU reflected his early work in processing signals for both imagery and sound. Of particular interest to our story, he helped develop a mathematical model of the inner and outer hair cells and the cochlea. This model of how the ear and brain detect and process sound allowed researchers to theorize how hearing begins to fail, and how to compensate for the damaged parts of the ear to provide a more natural hearing experience—a central goal of all of our devices.
Soon, Dr. Chabries and Dr. Thomas Stockham, a digital sound pioneer at the nearby University of Utah, became aware of each other’s work, and began to collaborate on an idea they both were excited about: a low-power digital hearing device that could suppress noise and enhance speech. This device looked at human hearing as a total system, gathering information via the ear and processing it in the brain to provide a natural sound experience. Once Chabries and Stockham had produced a working prototype, they were joined by Dr. Carver Mead of Caltech, the father of microelectronics. Dr. Mead reduced the prototype to a tiny chip that fit comfortably inside the human ear and the first Sonic product, Natura, was born in 1998.
Like his Sonic founder colleagues, Dr. Chabries is a creative thinker with wide interests. He has worked in related areas, like visual imaging, to help us understand ancient texts from places like Petra and Herculaneum, as well as the Dead Sea Scrolls and Mayan glyphs. In many aspects of human experience and perception, Dr. Chabries has been both explorer and innovator.