Model Developed to Aid Research of High-Noise-Environment Hearing Protection Published Oct. 23, 2008 By Maria Callier Air Force Office of Scientific Research ARLINGTON, Va. -- Researchers funded by the Air Force, Army, and Navy are investigating ways to improve communication links for people wearing headphones, helmets, and other protective equipment in noisy environments. Their research has been an especially important collaboration for the military because many serving in the armed forces suffer from hearing impairment due to repeated exposure to aircraft engine sounds and large-caliber weaponry. Dr. Leszek Demkowicz is a University of Texas at Austin scientist whose expertise lies in constructing geometric models and corresponding finite-element code. He is working alongside other scientists who specialize in finite elements, geometry description, acoustics, and hearing science to conduct research about high-noise environments. Despite lacking a fundamental research base regarding the transmission of acoustic energy through nonairborne pathways to the cochlea, the researchers have persevered. They turned to earlier software tools as a basis for creating finite-element code that, in turn, helped them build a model of the human head. The model details the cochlear region and its interface with the skull and air pathways. To fully leverage the finite-element code requires a mathematical description of acoustical wave movement through the model. Because significant amounts of acoustic energy can reach the cochlea via nonairborne pathways, earmuffs, earplugs, and other ordinary hearing protection devices are rendered ineffective in its presence. Acoustic energy can consequently interfere with and degrade one's ability to localize the directions of sound sources and, further, can impede voice communications. This effort to examine hearing protection in high-noise environments is built upon two decades of research on higher-order finite elements for wave propagation problems, as documented by Dr. Demkowicz in his two-volume book, Computing with hp-Adaptive Finite Elements, and addressed in over 45 additional publications as well.