This volume contains 131 of the papers presented at the 22nd International Symposium on Acoustical Imaging. This meeting, which was held for the first time in Florence, Italy, on September 3-6, 1995, allowed an intense and friendly exchange of ideas between over 150 researchers from 26 different countries of Europe (70%), America (20%), Asia and Australia (10%). The Symposium started on Sunday, September 3, with the opening Session held in the magnificent 'Salone dei 500' in Palazzo Vecchio; this included invited talks by Peter WeHs and Hua Lee, who reviewed the State of the Art in Acoustical Imaging research. One hundred and forty papers, selected from the nearly