Research over the last decade has explored the relevance of psychoacoustic indicators such as Loudness (N), Sharpness (S), Roughness (R) and Fluctuation Strength (FS) for the description of the perceptual construct of soundscapes. Furthermore, the recent ISO 12913-2 standard, published in 2018, recommends their use for the quantitative assessment of soundscapes. However, usually, investigations on soundscapes are using averages of the psychoacoustic indicators, and little research has evaluated the relevance of percentiles for the perceptual description of physical environments in terms of geometrical features, prevailing noise sources, temporal and meteorological variables, etc.
This study aims to verify whether psychoacoustic percentiles can representatively describe the geometrical features of different urban sonic environments. For this purpose, recordings were taken in Aachen and Madrid in different days and seasons, at 14 certain locations in each town. In addition, morphological data was collected of the sites.
A Principal Component Analysis (PCA), conducted on psychoacoustic percentiles (i.e., P1, P5, P10, P50, P90, P95, P99) of N, S, R and FS and geometrical features (road, pedestrian sidewalk and propagation path widths, as well as building heights), showed well-defined components, highlighting the fact that some percentiles can describe specific geometrical features of the urban sonic environments.