Integrating Indoor Soundscape Approach into IEQ Research: Acoustic Comfort in Naturally Ventilated Residential Buildings

The present study investigates acoustic comfort in naturally ventilated residential buildings through an indoor soundscape approach. Preliminary results from a laboratory listening test are presented, where, in a mock-up living room with a window sight, participants have been exposed to 20 acoustic scenarios, obtained as a combination of 4 indoor sound sources and 5 outdoor urban environments filtered through a window ajar. Participants were asked to rate each exposure condition. Subjective ratings on 6 selected attribute scales related to valence and perceived control are here analyzed in order to: (1) study associations between (psycho)acoustic parameters and subjective judgments, and (2) investigate whether sounds released through natural ventilation could be beneficial to indoor soundscape. Repeated measures correlations showed a general stronger association between subjective ratings and loudness (N10). However, considering the effect of outdoor sound type and the interaction between outdoor and indoor sounds on acoustic perception added a fundamental layer of information to indoor soundscape characterization. Under some of the tested conditions, regardless their loudness, outdoor sounds could improve indoor soundscape in terms of increased comfort and reduced annoyance, alleviating feelings of helplessness when in presence of annoying indoor sources or silent indoor environments. Besides confirming the harmful effect of loud heavy traffic noise exposure, the study points out the positive effect of natural sounds on soundscape, and the benefits that can be offered to the indoor soundscape of a residential living room even by urban sounds, such as light traffic noise and human voices from a pedestrian area. The study shows the opportunities for IEQ research to address the apparent conflict between acoustic and ventilation needs from a perceptual, soundscape approach.