Relationship between the geometric profile of the city and the subjective perception of urban soundscapes

Large urban areas are very prone to be contaminated by different pollutants beyond safe limits. In recent years, it is not only pursued that these environments comply with all the regulations in this regard, but also to make them as comfortable as possible for their inhabitants. Being noise one of the most harmful pollutants, researchers and administrations are focusing their efforts in understanding and improving the subjective perception of the urban sound. This understanding could allow to make better decisions in the planning of large urban areas or in the efficient management of the traffic flow. The main purpose of this study is to evaluate if urban places with similar geometrical features are acoustically perceived in a similar manner. The study was conducted in the city centre of Madrid (Spain), where the sound was recorded in 13 places, and their geometrical features studied. In some of these places the recordings were performed more than one time, in different recording sessions, to study the acoustic stability of the environments. Psychoacoustic indicators were extracted and statistical analysis as well as clustering analysis were performed. A listening test was conducted to evaluate the agreement between the quantitative results and the perception of a sample of 16 participants. Both the quantitative and the qualitative analysis reported that urban places with similar geometries are perceived in a similar way. Also, it was proven that a recording performed a particular day in one place is highly representative of that place for similar working conditions. These results point out the benefits of incorporating the psychoacoustic indicators in the planning of large urban areas in order improve the acoustic comfort besides reducing the noise pollution. (C) 2019 Elsevier Ltd. All rights reserved.