Night noise control with sound recognition and nudging

Posted on 22 March, 2023

Night noise control with sound recognition and nudging

At the end of 2021, the Naamsestraat in Leuven was equipped with Munisense noise monitoring stations (sound meters) that provided sound recognition in addition to all usual noise parameters.

The set sound level in combination with defined sound recognition parameters were, after a period for the zero measurement, used as a trigger for testing various nudging techniques. The investigation by the City of Leuven has now been completed.

The nudging messages to the nuisance cause(s) that were projected directly onto the street proved to be most effective. These light projections reduced noise pollution by 30%.

And indicates the City of Leuven "Now we know what we can roll out throughout the city.".

Great to hear from such a satisfied and innovative customer! published the article below, with video about this research of sound measurements and sound recognition in combination with nudging in Leuven.

Light projections are the answer to Leuven's night noise problem. This has emerged from research that the city carried out together with, among others, KU Leuven and the police during the past year. Using Munisense sound meters, they tested the impact of various nudging techniques, and only the light projection turned out to really help.

“Leuven is traditionally a real nightlife city. That is nice of course, but it also brings night noise. Those who want to live in the real entertainment center, for example above a café on the Oude Markt, opt for this. However, the night noise also spreads in several streets that are further from the real center. And that is, to say the least, disturbing for those who have to appear at work fresh and cheerful the next day. A bustling city is very valuable, but so is a good night's sleep,” says alderman Thomas Van Oppens (Groen).

In the past, people already worked with posters, or people walking around with T-shirts with the inscription 'Silence'. Now, however, the city decided to play its innovative card and really use smart technology to investigate what could dampen the decibel peaks.

Thursday night

Between August 2021 and November 2022, the city mapped the noise nuisance with seven noise meters between the Collegeberg and the Stuk arts center. They registered peak noises of 70 decibels or more, between 11 pm and 5 am. “The baseline measurement immediately taught us that a lot of night noise is registered, especially in the night from Thursday to Friday. Then Wednesday and Tuesday. The weekend is remarkably quiet.

On Wednesday and Thursday there are peaks of an average of 88 decibels, comparable to the noise of a lawnmower. The noisiest month was October 2022, the start of the academic year. March 2022 also scored poorly. Then the last corona measures were lifted. “In total, we registered more than 1,000 peaks that we can label as night noise,” it sounds.


No posters
The research did not stop there. “We also investigated which nudging techniques reduced night-time noise. It soon became apparent that hanging posters or stickers on the street had no effect at all,” says Van Oppens.

The police also tested whether they could mean anything by following the sound data and immediately rushing to the scene in the event of a peak, looking for and addressing the 'perpetrators'. “That turned out to be useful when we found them, but it was very labour-intensive and it often involved such a short peak that we no longer found the people involved by the time we arrived,” says student cop Gil Vanommeslaeghe.

‘Here sleeps: Mohammed (5)’

What clearly worked was a light projection. “We projected a message 'silence zone', including names and ages of people who 'sleep here'. Successfully. The projection clearly reduces nuisance, by no less than 30 percent. We do notice that it mainly had an effect up to about 1 o'clock, and less with people who came through the street at 3 o'clock, for example. Perhaps because they are more tired or drunk, and therefore less alert to the message,” says Van Oppens.

The aldermen and all organizations involved speak of a very successful investigation. “We now know when to intervene, and how best to do it,” says Van Oppens. “The investigation is now over and the projection is gone. It is our intention to roll this out in other streets in Leuven and to conduct even more research. Consider, for example, the Tiensestraat or Brusselsestraat, where there are also many complaints of nuisance. In this way we can reduce night noise without the police having to intervene.”

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