Framework for urban sound assessment at the city scale based on citizen action, with the smartphone application NoiseCapture as a lever for participation

Abstract

The development of citizen-based approaches to the diagnosis and decision-making on urban noise environments responds to a demand from both local authorities and residents. However, the methods for fostering the involvement of citizens and the valorization of local knowledge have yet to be invented. This article reports on a co-constructed experiment between researchers and local authorities, in the city of Rezé (France), of an urban noise diagnosis based on the residents and the use of the smartphone application NoiseCapture, which allows a participative measurement of sound levels. The framework also includes focus group discussions. The dynamics of the recruitment and data collection phase are analysed, showing the importance of creating public events around the initiative. Maps of noise levels, but also of the presence of sound sources, such as road, rail and air traffic, or animals, are produced in a collaborative way. Finally, the focus group discussions highlight that (i) repeated noise measurement modifies participants’ relationship to sound environments; (ii) NoiseCapture enhances the formation of a group of residents active on noise issues. Such a framework can provide a citizen-based basis for decisions on noise environments; the next step will be to study its adaptability to different territories.

Blind Calibration of Environmental Acoustics Measurements Using Smartphones

“…These data can then be used to produce noise maps for the benefit of local authorities, for example, in the context of establishing action plans to reduce noise pollution. The project can also be part of an educational [ 13 , 14 ] or citizen approach to raising awareness and the co-construction of public policies [ 15 , 16 ]. Whatever the purpose of the collected data, the calibration of smartphones is an issue that is often discussed.…”

“…In the NoiseCapture approach, specific events can be specifically organized in order to collect acoustic data over a defined spatial extent and over a given period. These events, called NoiseCapture Parties, are organized, for example, by researchers to collect data on a specific territory as part of their research into exposure to noise pollution [ 41 , 42 , 43 ], by teachers to train school and university students in environmental noise issues [ 14 ], or by local authorities wishing to raise awareness on the subject of noise environments [ 16 ]. In general, these events are run by professionals who are very familiar with the practice of acoustic measurement in the environment.…”

“…The previous analysis is now extended to the City of Rezé, part of the Nantes metropolitan area, in France ( Figure 9 ), for which a very large amount of data has been collected, both in the context of NoiseCapture Party events (NoiseCapture Party N°2, N°9, and N°52) and by “independent” contributors. In this area, additional data have also been collected similarly to a NoiseCapture event, in the framework of the Sonorezé research project [ 16 ], but are not a part of NoiseCapture Parties. The involved area represents a surface of 13,780,000 m 2 , gathering a total of 450,335 of 1 s measurement points and 2336 tracks on 10,365 hexagons ( Figure 10 ), collected by 331 (smartphone, user) pairs with 163 different smartphone models.…”

“…This is visually accentuated in the neighbourhoods where few measurements contribute to the estimated value for each hexagon. This is the case for instance in the northwest where the density of measurements is small (see Figure 6 of Reference [ 16 ]).…”

Investigating Noise Mapping in Cities to Associate Noise Levels with Sources of Noise Using Crowdsourcing Applications

“…For large cities, challenges have to be met in terms of data management, data reduction, calculation methods, optimization procedures, validation techniques, and the presentation of results so that the maps can serve as powerful tools to be used for urban noise planning and design. Noise management and reduction plans must be based on a general strategy for the management of urban areas, considering the land uses, the means of transportation, and the dynamic development of the city [44].…”