Dr. Charles H. Sherman received the B. S. degree from the Massachusetts Institute of Technology and the M. S. and Ph. D degrees from the University of Connecticut. He worked mainly at the Navy Underwater Sound Laboratory in New London, CT, but also at Tracerlab, Inc. in Boston, MA, and Parke Mathematical Laboratories in Carlisle, MA, and now works at ... Read moreImage Acoustics, Inc. He has presented and published over thirty papers related to acoustics and transducers, and was elected Fellow of the Acoustical Society of America in 1974. He taught advanced acoustics at the University of Connecticut and transducers in the Ocean Engineering Department of the University of Rhode Island. He has over 40 years experience in underwater sound transducers and arrays. Dr. John L. Butler is President and Chief Scientist at Image Acoustics, Inc. and has had over thirty five years of both practical and theoretical experience in the design and analysis of underwater sound transducers and arrays. He has worked for Harris Transducer (now Harris Acoustic Products Corporation), Parke Mathematical Laboratories, Massa Products Corporation and Raytheon Company, consulted to a number of underwater acoustics firms and the U. S. Navy, taught courses in acoustics, holds seventeen patents on transducers and has presented or published over thirty papers on electroacoustic transducers. In 1977 he was elected Fellow of the Acoustical Society of America. His education includes: Ph. D., Northeastern University, Boston, MA, and Sc. M., Brown University, Providence, RI. Show Less