Over the past few years, in the civil engineering eld, the structural health monitoring technique which exploits Coda Wave Interferometry has found its breakthrough. Among the several non destructive tests, the use of ultrasonic wave propagation and scattering has started to show useful and promising characteristics in the task of heterogeneous media inspection (e.g. concrete). The present study deals with the investigation and discussion of such sensing technique, by means of a synthetic and a real analysis. Basically, instead of being focused on the rst arrivals, this theory employs the late section of the signal. In fact, while scattering throughout the element, these coda parts of the signal undergo some variations, experiencing a characterisation of the medium signature.