Sound Water Masking to Match a Waterfront Soundscape with the Users’ Expectations: The Case Study of the Seafront in Naples, Italy

In the last decades, the soundscape approach has attracted the attention of architects and urban planners, leading them to incorporate the acoustic features into the enjoyment of their creations. One of the key aspects for an appreciated urban environment is to match the expectations of the users. In this study, the matching of the waterfront soundscape with the users’ expectations is evaluated by laboratory tests using semantic differential scales applied to reproduced virtual scenarios obtained adding different water sound pressure levels (SPLs) to the original in-situ setting. The tests were carried out by an immersive virtual reality (IVR) device, using 360° videos and spatial audio recorded in two sites of the waterfront in Naples, Italy. The scenarios were presented to the participants according to three experimental protocols, namely audio-only (A), video-only (V), and simultaneous audio-video (AV) reproduction. The examined different acoustic scenarios were the original one recorded in situ and others obtained adding seawater sounds at SPL increments of 5 dB. The results show that all the scenarios with water sounds added are rated more pleasant than the original one for the audio-only scenario. When video and audio are displayed simultaneously, two scenarios are more pleasant than the original one, likely because there is a need for coherence between the water sound SPL heard and the visible noise sources. Sounds coherent with the type of shore show a higher matching with expectations and pleasantness appraisals, rather than those that are uncoherent with the layout scenario.