Dr. John L. Butler is Chief Scientist at Image Acoustics, Inc. and has had over forty years of both practical and theoretical experience in the design and analysis of underwater sound transducers and arrays. He has worked for and consulted to a number of underwater acoustics firms as well as Parke Mathematical Laboratories and the U. S. Navy. He has also taught courses in acoustics at Northeastern University, Naval Air Development Center, Raytheon Company, Harris Transducer Products and Hazeltine Corporation (now Ultra Ocean Systems, Inc.), Massa Products Corporation, Etrema Products, Plessey Australia, and Lund Institute of Technology, Sweden. He holds twenty seven patents and has presented or published well over thirty papers on electro-acoustic transducers. In 1977 he was elected fellow of the Acoustical Society of America and has received their 2015 Silver Medal Award for advancing the field of acoustic transducers and transducer arrays. His education includes Ph. D., Northeastern University, Boston, MA, and Sc. M., Brown University, Providence, RI. Dr. Charles H. Sherman (1928-2009) received a B. S. degree in physics from the Massachusetts Institute of Technology in 1950. After his first job at TracerLab, Inc. in Boston, he became a research physicist at the Naval Underwater Sound Laboratory in New London, CT. He received M.S. and Ph.D. Degrees from the University of Connecticut and was elected Fellow of the Acoustical Society of America in 1974. He became a prominent expert in underwater transducers and arrays, presenting and publishing over thirty papers related to underwater acoustics. He also worked at Parke Mathematical Laboratories in Carlisle, MA, and taught advanced acoustics at the University of Connecticut and in the Ocean Engineering Department of the University of Rhode Island. He received the prestigious Decibel Award, which is presented to a scientist or engineer for outstanding contributions to sonar and underwateracoustics. After his retirement from the Sound Lab in 1988, he worked for Image Acoustics, Inc. and in 2007, co-authored the first edition of Transducers and Arrays for Underwater Sound, a technical monograph commissioned by the Office of Naval Research and the most comprehensive treatment to date of underwater transducers and arrays.
