This volume contains forty-six of the papers presented at the Ninth International Symposium on Acoustical Imaging held December 3-6, 1979, in Houston, Texas. The theme of the confer- ence was the integration of applications technology. The major objective of the conference was to promote interaction among researchers working on different applications of acoustical imaging. In addition to serving as a state-of-the-art research ref- erence, this volume includes six tutorial review papers. For convenience, all the papers are grouped under the following headings: methods, transducers, processing...