Integrated Non-Intrusive Methods for the Acoustic Characterization of External Noise Sources on Cruise Ships

Abstract

External noise emitted by large cruise ships both in port and near the coast is a topic of increasing regulatory and environmental interest. Cruise ships are complex systems that generate significant noise, affecting both the onboard environment and the surrounding areas. The primary noise sources are often associated with funnels and auxiliary systems, with the ventilation and air conditioning systems acting as particularly critical and acoustically complex emission points. Non-intrusive acoustic measurements (intensity probes, sound level meters, and acoustic camera) are ideal for noise source characterization, allowing for accurate, real-time spatial mapping. This work presents the results of a preliminary experimental campaign conducted on a cruise ship both onboard and in a shipyard to characterize noise sources and assess noise propagation. Onboard noise levels were measured using sound level meters and intensity probes, which enabled the identification of key areas of interest. In parallel, an acoustic camera was employed to analyse the spatial distribution of the emitted noise. The comparison between measurement data and acoustic camera outputs revealed key practical and methodological limitations, highlighting the value of this preliminary campaign in refining the approach for future, more comprehensive investigations.