MASANOM: Mobile acoustic sensors to generate automatic noise maps for cities

The fast development of communication networks and the reduction in price of electronic components has put many European cities in a race to gather large amounts of data (on noise, air quality and traffic) and share them with inhabitants through web and mobile applications. In addition, the constant evolution of the Smart City concept is leading to an improvement in citizens’ comfort levels.

Among the main polluting factors, noise pollution is often overlooked as a health and environmental problem. However, according to the WHO, exposure to high, continuous levels of noise can cause serious illnesses such as cardiovascular problems.

To calculate the population’s exposure to environmental noise and to design and apply action plans to reduce it, European Directive 2002/49/EC defines an environmental noise map as an image of the levels of noise from different sources and time intervals. According to this directive, from 2019 it is compulsory to calculate noise maps by simulation, using the CNOSSOS-EU model. However, concerns have emerged regarding this method, as the results depend on the calculation procedure and a large amount of data are required to obtain a noise map.

In this context, the MASANOM project emerged. The main objective is to develop a method to generate and automatically update noise maps in cities, using a set of low-cost mobile acoustic sensors, which emit a low background noise and can be mounted on vehicles that move continuously around the city, for example, bicycles and electric scooters.

As part of the project, annual values of Lden and Ln (the average noise level during the day, evening and night) will be measured, as they should be plotted on a noise map according to the European directive. However, noises limited in time and space or those that occur at specific times and specific places are not detected. 

The network of mobile sensors will move continuously around the city and thus provide, over time, the spatial and temporal sampling requirements needed to produce accurate noise maps. In addition, the noise maps drawn up with this system will be updated continuously by adding recently received data. This will be an advantage in terms of the five years of validity and compulsory renovation of noise maps established by the directive.

Due to this continuous updating, it will be possible to detect excesses in the capacity maps (maximum levels of noise permitted in an area) in a shorter time. This will mean that maps can be updated with greater speed and therefore more accurate action plans can be proposed to reduce the noise pollution and increase citizens’ quality of life.

In addition, the use of low-cost measurement stations will reduce the expenditure associated with the creation of noise maps and make them more attainable for developing countries, in which traffic noise is a considerable problem due to the presence of very dense traffic jams and an older fleet of vehicles.

Budget and funding

MASANOM has a total budget of €173,500, through the call for subsidies Knowledge Generation Projects 2022 (Spanish State Research Agency) of the State Plan of Scientific and Technical Research and Innovation 2021-2023 (Ministry of Science and Innovation). Its duration is three years (2023-2026).