Recently the rising concern about the environmental impact of ship noise on the marine fauna pushed national and international bodies to face the problem. In the last decade a few mass strandings of cetaceans due to sea trials of navy sonars, enforced the interest on noise pollution effects on marine mammals. The problem of evaluating the impact of underwater noise from ships is very complex due to the difficulties in characterising the whole noise chain ( source, transmission path, receiver). As regards the source, ships are characterised by complicated emissions due to the superimposition of different sources (propeller, machineries, flow noise); moreover, because of their dimensions, the measurement procedure is long and complicated. At this aim, very recently, some standards have been issued aimed at the measurement of underwater noise emitted from commercial ships. As regards the transmission path, problems are linked with the correct evaluation of the transmission loss which is influenced by many environmental parameters (water temperature, salinity, pressure, bottom composition etc.) which cannot be easily monitored during measurements. Finally the actual sensibility to noise of the marine mammals it is not completely known, especially for species belonging to the Mysticetes (Baleen Whales).

 These problems have been analysed in the SILENV collaborative project  (Ships oriented Innovative soLutions to rEduce Noise & Vibrations), devoted to the holistic analysis of noise emissions from the ship [radiation inside the ship and outside (in air and in water)]. The project is funded by the E.U. and has been launched in 2009. Again within the 7^th Framework Programme a call was launched on the specific subject of underwater radiated noise, focussed on the noise from cavitation. Presently the selection process is undergoing