The aim of this paper is both: to introduce the project called HESPERIA (homeland security: technologies for the security in public spaces and infrastructures) and to describe the task about acoustic surveillance in the project. The objective of HESPERIA consortium is the development of technologies to allow the creation of innovative security systems, video surveillance and operation control in infrastructures and public spaces. The project will try to substantially increase the security on especially strategic infrastructures like electrical substations, water deposits or telecommunication centers and in big public spaces like airports, railway stations, ports and urban environments as pedestrian areas, shopping centers, etc. The task of the Univerity of Las Palmas de G.C. in this project is the acoustic monitoring leading to fault diagnosis and prediction of electrical machines in power stations to increase their security, to decrease the maintenance cost and to reduce the time between faults of power supply.