The Acoustic Emission (AE) technique uses ad hoc transducers to detect AE events caused by crack growth in structures under external loading. This technique is similar to the one employed in earthquake control, where seismic waves reach the monitoring stations placed on the surface of the Earth. And although they take place on different scales, these two phenomena - damage in structural materials and earthquakes in geophysics - are very similar. In both cases a release of elastic energy from sources located inside a medium occurs.

Both earthquakes and AE signals can be seen as...