A system for controlling the quality of industrial processes including the steps of: having one or more reference signals relating to the industrial process, acquiring one or more real signals which are indicative of the quality of said industrial process, obtaining a transformed signal from the reference signal, obtaining a transformed signal from the real signal, calculating energies of the transformed reference and real signals, comparing the one or more reference signals to the one or more real signals to identify defects in the industrial process. Also, the comparing step includes: comparing the energies of the transformed reference and real signals to each other to extract corresponding time frequency distributions for selected frequency values, calculating energies of the time frequency distributions, and comparing the energies of the time frequency distributions with threshold values to identify energy values associated to defects.