NoiseCapture: become an urban noise hunter!

Noise Capture is a free application developed by the CNRS and IFSTTAR which allows users walking around in urban areas to use their smartphone to measure their sound environment. The ultimate goal is to gain a better understanding of the burden of noise pollution for city dwellers.

In the framework of the European ENERGIC-OD project the CNRS1 and IFSTTAR have developed an amazing smartphone application which has been christened NoiseCapture. Its purpose is to create noise maps of urban areas. Five IFSTTAR scientists from the Nantes-based Environmental Acoustics Laboratory (LAE) have been working on this completely free “App. “Our specialization is developing tools and methods for better evaluating our urban sound environment”, Judicaël Picaut, the LAE researcher who led the project, explains.

But how does it work in practice? The app has been designed for Android smartphones and measures our sound environment when we walk around in an urban environment, and, by using tags, is even able to assess the impression it makes on us. But NoiseCapture is also connected to a dedicated data processing system in order to process all the geolocated noise data. The recorded data is sent to a server that aggregates it with data from the other contributors then displays the result in the form of noise maps. 

More realistic noise maps

The goal is to produce noise maps that are more realistic than those that have been produced hitherto using conventional modelling techniques.

Thanks to NoiseCapture, we can capture all the sound sources, not only those we can model… and in real time too!

Judicaël Picaut explains. Some noise maps that display the raw data provided by participants are already on line.

The main challenge now is to manage to “clean up” the data with regard to the accuracy of the GPS, the calibration of measurements, etc. In practice, the CNRS hosts the noise maps and data while the Open Source computer code is hosted online on IFSTTAR’s page on the GitHub platform. Local authorities, researchers firms… all the actors with an interest in urban noise can also download the raw data for their own needs, as Open Data from a database.

Already 300 contributors from 40 countries

The beta version of NoiseCapture has already been tested by 300 contributors from 40 countries. This has generated 3,000 sound journeys, with 500,000 measurement points, i.e. the equivalent of six days of continuous measurements. “This is still not enough to obtain to obtain accurate noise maps which focus sufficiently on the same zones”, Judicaël Picaut regrets to say.

But the researchers are counting on the release of the final version, scheduled for early September 2017, to create even greater enthusiasm. A first “NoiseCapture Party” will even be organised for people to learn how to calibrate the microphone on their smartphone before going noise hunting in the target districts. Privacy is not a concern either, as it is impossible to identify or record a contributor with NoiseCapture, only noise level indicators are computed.

So are you ready to take part in an exciting participative science project?

 

1. Lab-STICC belongs to the CNRS and is located in Vannes in Britany.