Road traffic noise affects annoyance during urban built and forest walks, but not repetitive negative thinking or connectedness with non-human nature: A randomized controlled trial.

Road traffic noise annoyance was lower in forest settings than in urban built settings.

• Study used a randomized controlled trial design with 354 healthy adults in Zürich, Switzerland
• Participants completed 30-minute walks in forests and urban built environments
• The association between road traffic noise and annoyance was 'particularly pronounced in forests'
• Registered in the ISRCTN registry (ISRCTN48943261)

Road traffic noise annoyance was lower in lower road traffic noise settings than in higher road traffic noise settings.

• Study compared varying levels of road traffic noise across walk conditions
• Both environment type and noise level independently contributed to annoyance outcomes
• Results 'underscore the role of road traffic noise as a significant health-related stressor'

Road traffic noise annoyance was lower in areas with longer relative quiet time than in those with shorter relative quiet time.

• Relative quiet time refers to the temporal pattern of noise intervals during walks
• This finding extends annoyance prediction 'beyond average noise measurements'
• Results 'highlight the relevance of quiet intervals and temporal noise patterns in shaping perceived annoyance'

Walking in forests was not associated with a greater reduction in repetitive negative thinking compared to urban built environments.

• Repetitive negative thinking was measured as a maladaptive emotion regulation strategy
• Data from 354 healthy adults were analyzed
• Neither environment type (forest vs. urban built), lower road traffic noise, nor longer relative quiet time was associated with greater reduction in repetitive negative thinking

Walking in forests was not associated with a stronger increase in nature relatedness or love and care for nature compared to urban built environments.

• Two dimensions of connectedness with non-human nature were assessed: nature relatedness and love and care for nature
• Neither environment type, road traffic noise level, nor relative quiet time predicted changes in either connectedness measure
• Previous research had suggested greenspace exposure might foster connectedness with non-human nature

The robust association between road traffic noise and annoyance was particularly pronounced in forests compared to urban built settings.

• This finding suggests forests may be especially sensitive to road traffic noise as a stressor
• The authors interpret this as supporting 'the need for targeted noise mitigation—particularly around urban forests—to preserve their restorative potential'
• The interaction between environment type and noise level on annoyance was a notable finding