Sabih Hayek, Professor Emeritus of Engineering Science and Mechanics, presented a paper entitled "Acoustic Backscattering from Fluid-filled Submerged Spheroidal Shells", at the 4th Joint meeting of the Acoustical Society of America and Acoustical Society of Japan, held in Honolulu, Hawaii, November 28-December 2, 2006. The paper was co-authored with Jeff Boisvert (National Undersea Warfare Center, Division Newport, Newport, RI). Dr. Hayek also chaired the session on Structural Acoustics and Vibration.