Marshall H. Orr received the Ph.D. degree in 1972 in low-energy nuclear physics from the Pennsylvania State University (PSU), State College.
He was employed as an Assistant Professor of Physics at the PSU Sharon Campus and a Research Associate at the PSU Applied Research Laboratory before joining The Woods Hole Oceanographic Institution (WHOI) as an Assistant Scientist in 1974. He left WHOI as an Associate Scientist in 1981 to work first as a Geophysicist at Gulf Oil Research and Development Company and then Standard Oil of Ohio before joining the Office of Naval Research (ONR) in 1987 as a Scientific Officer. He became the Program Manager of the ONR 6.1 Ocean Acoustics Program in 1988. He joined the Naval Research Laboratory, Washington, DC, in 1992 and presently is the Branch Head of the Acoustic Signal Processing Branch, Code 7120. His research interests include random media propagation physics, high-frequency acoustic flow visualization of turbulence and internal waves, and the generation, dispersion, and decay of internal waves, acoustic communications, and advanced ASW signal processing concepts.