Are the comfort classes noise and vibration levels on board really suitable?

In shipbuilding industry, comfort is a relevant issue both for crew members and passengers. A comfortable environment enables crew members to perform accurately their tasks and it is an effective factor contributing to the satisfaction of passengers. Noise and vibration, as envi-ronmental parameters, play an important role in subjects’ comfort. Naval Classification Socie-ties established a series of noise/vibration comfort level criteria, which, however, do not take into account two aspects: noise/vibration recordings are carried out during time periods much shorter than the exposure time of crew/passengers; the subjective mood is not considered at all to asses comfort. In the present study, we studied comfort perception by measuring heart rate variability and mood. We exposed participants to four levels of acoustic noise [from 45 to 55 dB(A)] and three levels of vibration (1.5, 1.8, 2 mm/s) inside a full-scale mock-up of a cruise ship cabin. We found a general increment of heart rate variability and negative mood while in-creasing the noise/vibration intensity. However, the changes in comfort responses did not oc-cur for the noise/vibration comfort thresholds identified by the Classification Societies. Our re-sults evidence the importance to include a psychophysiological measure of comfort when de-fining comfort criteria on board.