Factors influencing noise annoyance across various transportation modes: lessons from the citizen science project "De Oorzaak"

The citizen science initiative "De Oorzaak" invited adult residents of Flanders (Belgium) to fill out the "Large Sound Survey", gathering over 8,000 answers in a month. This comprehensive 51-question survey evaluated annoyance levels across various transportation modes, drawing on established questionnaires like the Epworth Sleepiness Scale, Weinstein Noise Sensitivity Scale and Written Environmental Survey (SLO), organized by the Flemish government. It also aided in selecting participants for subsequent project phases. Comparing LSS results to the latest SLO report revealed a significant self-selection bias, with 33.3% highly annoyed by noise compared to 11.6% from the SLO. A profile could be drawn for the most annoyed participants: noise-sensitive individuals living in apartments or studios, adults (26-61 years old), and residing in densely populated areas. Regarding transportation noise, passenger cars and trucks lead as the most annoying sources, with %HA of 24.5% and 23.5%, respectively, followed by motorcycles and alike (%HA =21.5%). Conversely, rail and air traffic annoyance are considerably lower. Correlations were drawn between the several noise annoyance sources and individuals' characteristics. Overall, population density, age, fatigue level and quality of life are the personal aspects that correlate more consistently with road, rail, and air traffic noise annoyance.