A variety of information related to acoustic emission has been compiled in this book. Acoustic Emission (AE) is a phenomenon in which elastic or stress waves are produced from speedy, localized change of strain energy in substances. The practical function of AE first emerged in the 1950s, but it is only in the last two decades that the science, technology and applications of AE have progressed notably. At present, AE has become one of the most significant non-destructive testing methods. This multidisciplinary book contains data which demonstrates that the AE method is constantly rising and extensively functional in on-line monitoring of civil-engineering constructions such as flyovers, buildings, etc. AE is also applied for the exposure of fatigue cracks and their positions in complex vessels and pipelines, damage estimation in fiber-toughened polymer-matrix compounds, among others. This book will be helpful for both students and experts interested in this field.