Acoustic impact of ships: Noise-related needs, quantification and justification

The evaluation of the acoustic impact of ships is a complex problem, involving not only different sources but also different kinds of receivers and transmission paths. The problem of health and comfort for crew and passengers on board has been considered since a few decades, leading to quite a structured and detailed framework of Norms and Requirements. On the other hand, only in recent years a growing attention has been devoted to air-borne noise emissions outside the ship, for which requirements are not present. Underwater noise emissions have, even more recently, gained attention for their potential interference with mammals' communications and with the sophisticated use such animals make of acoustic signals for interacting with their living environment. An aim of the present work is to review the state of the art in the three areas above identified outlining the differences in the specific fields as regards: The present knowledge of the phenomena involved; the accuracy of the models available for the description of noise propagation; the accuracy of the models available for the quantification of noise effects.