Spatial aspects in urban soundscapes: Binaural parameters application in the study of soundscapes from Bogotá-Colombia and Brasília-Brazil

Abstract

Acoustic environment studies traditionally use monaural energetic parameters as the main acoustic descriptors, which are associated with acoustic comfort and/or noise annoyance. However, under the soundscapes paradigm, it is necessary to explore other acoustic parameters that characterize not only energy levels but also temporal and spatial aspects of the acoustic environments. This paper’s goal is to deepen the study of urban soundscapes, considering the sound sources’ variation in the horizontal plane and determining the relationship of this phenomenon with subjective and descriptive aspects. The objective and subjective aspects of 10 soundscapes in the cities of Brasília (Brazil) and Bogotá (Colombia) were evaluated using fragments of binaural sound recordings. For objective analysis related to spatial behavior of sound sources, Interaural Cross-correlation Functions (IACF) in running and long-term modalities were applied to obtain the Interaural Cross-Correlation (IACC), the Interaural Time Delay (τIACC) and Width of IACC (wIACC). The subjective assessment laboratory tests involved a panel of 25 listeners to evaluate different perceptual attributes and descriptive aspects of the soundscapes. The results indicate that there is a correlation between some binaural parameters derived from the running IACF and different perceptual attributes. Thus, spatial aspects, such as the variation of the sound sources in the horizontal plane, may have implications on perceptual attributes.