Research teams at NASA's Glenn Research Center are developing theoretical models and software for predicting the noise produced by aircraft engines. These developments are designed to assist engineers in designing and analyzing new as well as improved aircraft engine systems. Copies of the developed software can be obtained through the NASA software catalog. One area of work involves creating programs for predicting jet engine noise, known as JeNo. Development of such codes represents a complex and multifaceted task, involving modeling various aspects of acoustic noise generation and propagation. Work on such tools is important for the aviation industry as a whole, since reducing aircraft engine noise remains one of the priority areas for the development of civil and military aviation. Accurate prediction of engine acoustic characteristics at the design stage makes it possible to reduce costs for subsequent testing and refinement, and also contributes to the creation of quieter and more environmentally friendly aircraft. Glenn Center is one of NASA's key research divisions specializing in aviation and space technologies, including propulsion systems, communications systems, and materials science.