Sound design strategies in composing pleasant and unpleasant acoustic environments inside a living room in a European residential context

Abstract

Acoustic comfort arouses interest in sociology, psychology and building industry since the sixties. It can be defined in first approach as the absence of unwanted sounds and the presence of adapted sounds while doing an activity. Comfort is influenced by the acoustic performances of building, by the various types of sound sources, and by individual attitudes (sociological background, musical preferences etc.). In this study, the impact of sound sources on the pleasantness of typical domestic ambiances is investigated using a ?sound design? approach when a composition of sounds is listened coming from three distinct spatialized channels (from outside, from inside the room and from the neighbor). Via a computer interface, 65 people had to adjust the level of the three channels while keeping the overall equivalent level constant at 40 dB(A) in order to design optimized sound scenes. The compositions of the most pleasant sound environments were obtained in reducing SPLs of the neighbor sounds in most situations (TV. documentary, children, work, and party). Two sound masking strategies were revealed. One group preferred to increase the ventilation noise level in the room by 1.5 dB(A), the other group increased sound levels from outside by 2 dB(A). Alternative strategies are found for the two types of musical sounds coming from the neighbor. For classical music, most participants increased in average its sound level by 2 dB(A) Regarding Pop. music, sound preferences lead to 3 sound strategies. People who like Pop. music increased the sound level of this sound source by 3dB(A) in average. One group mixed it with the ventilation in the room, the other with sounds from the outside of the building. People who dislike the Pop music stimulus reduced its sound level by 4.5 dB(A) in average and increased the sound level of the sources coming from the outside.