This volume contains the papers presented at the Seventh International Symposium on Acoustical Imaging and Holography. The meeting was held in Chicago, Illinois U.S.A. on August 30 - September 1, 1976. Since 1967 this series of conferences has served as an international forum for bringing together the many different facets of the ultrasonic visualization field. Medical diagnosis, nondestructive testing, underwater viewing, seismic the mapping, and acoustic analytical microscopy are examples of broad range applications of this technology. Throughly broad in scope, the common denominator that binds this volume together is the application of engineering and physics disciplines to the creation of images by means of ultrasonic waves. Efforts on the part of the program committe and their institutions are greatly appreciated, They are acknowledged below: Newell Booth Nave lex Arlington, Va. Byron B. Brendan Holosonics, Inc. Richland, Wa. Reginald C. Eggleton ICFAR-IU Medical School Indianapolis, In. Stanford Research Institute Philip S. Green Menlo Park, Ca. Henry Karplus Argonne National Labs Argonne, Il. J.D. Meindl Stanford University Stanford, Ca. Alexander F. Metherell University of California Irvine, Ca. R.K. Mueller University of Minnesota Stillwater, Mn. Frederick L. Thurstone Duke University Durham, N.C. vii viii PREFACE Glen Wade University of California Santa Barbara, Ca. Keith Wang University of Houston Houston, Tx.