Measurement methods for the assessment of noise impact of large vessels

The noise emissions evaluation of large vessels is often an underestimated issue. In recent years, the evolution of ship design has been characterized, both for commercial and cruise ships, by the growing tonnage and the increasing number of sound sources present on board. Consequently, the determination of acoustic emissions of sources so large and complex requires the development of measurement techniques that need to be always adapted to the specific context of analysis and operational procedures of the vessel. Despite there being many references that can be found on technical standards, the majority of measurement methods are devoted to specific types of ships, mainly of small size, and it’s difficult to fit these evaluation procedures to large vessels. In the present paper a comparison between different measurement techniques and evaluation methods is reported, with reference to airborne noise emission in the external environment of large vessels during procedures of navigation, manoeuvring and mooring.