Yorkshire & North East Branch

If you want to know how residents actually experience the sound around them, annual average indicators only take you so far. De Oorzaak set out to close that gap, and this meeting is a chance to hear what a study of that size revealed.

De Oorzaak ("The Cause") brought together more than 10,000 citizen scientists with the University of Antwerp, Antwerp University Hospital, the newspaper De Morgen, industry and government, to measure and understand environmental noise in Antwerp, Ghent and Leuven.

The measurement campaign put smart noise sensors on the façades of 1,452 homes for six weeks each, alongside 73 fixed locations monitored for a full year. The sensors recorded acoustic parameters continuously and used on-the-edge AI to categorise noise events into nine source categories, so that annoyance could be related to the sources and to peak events rather than to Lden alone. That objective dataset sits alongside the Great Noise Survey (10,138 respondents), weekly surveys from 1,578 participants, soundwalk surveys, and a health study at Antwerp University Hospital in which 101 participants underwent a night of polysomnography at home with simultaneous indoor and outdoor sound measurement, saliva cortisol sampling and audiological testing. The survey population is self-selected - those more annoyed by noise, or more sensitive to it, were more likely to take part, so it cannot be read as representative of Flanders.

Some of the findings are expected: road traffic accounts for 38% of identified noise events and is by far the largest source of reported annoyance; front façades average 5 – 6 dB higher than rear or side façades; annoyance rises with L_den, with L_night, and with the number of events above 70 dB(A).
Others are less expected: no statistically significant relationship was found between night-time sound levels and overall sleep structure - though with only 101 participants, and with the micro-arousal analysis still to come.

The recommendations go straight to questions we are still discussing in the UK: that correlation between long term acoustic indicators and annoyance is limited (known but often forgotten); that limit values should explicitly account for noise dynamics and peak exposures; that noise-sensitive rooms should be sited on the quiet side; that natural sounds appear to buffer annoyance and belong in urban design; and the importance of expectations when evaluating experience.

This data invites us to think beyond regulatory compliance.

About the speaker: 

Prof. Cedric Vuye is a Associate Professor in the Faculty of Applied Engineering at the University of Antwerp, where he leads the section on Pavement Surface Characterization and Functionalization within the SuPAR research group. He is project lead of De Oorzaak, a large-scale citizen science initiative in Flanders, Belgium, combining smart noise sensors, citizen surveys and health studies across Antwerp, Ghent and Leuven to understand urban noise exposure and its impact on wellbeing. His broader research covers noise-reducing road surfaces and road traffic noise mitigation, and he has (co-)authored 55 journal papers and secured more than €6.5 million in research funding.
https://www.uantwerpen.be/en/staff/cedric-vuye/