The influence of traffic noise on restorative effects in green space

Urban green spaces provide vital restorative benefits for public mental health, yet traffic noise widely undermines these effects, with existing studies predominantly focused on sound pressure level rather than temporal and frequency characteristics of traffic noise. An outdoor experiment was conducted with 33 participants to investigate traffic noise impacts on urban green space restorative effects, assessing objective attentional restorative effects and subjective restorativeness (Perceived Restorative Soundscape Scale) under varied sound pressure levels, temporal discontinuity, and frequency conditions. Results showed that traffic noise consistently reduced subjective restorativeness, with negative effects intensifying as sound pressure level increased and weakening with greater temporal discontinuity. Medium-low frequency noise produced stronger detriments than medium-high frequency noise for both subjective and objective restoration. Objective restoration shifted from impairment to improvement as temporal discontinuity rose and showed a significant interaction between sound level and time-domain characteristics. Effect sizes further indicated that subjective restorativeness was more sensitive to sound pressure level, whereas objective restoration responded more to temporal characteristics. These findings clarify multi-dimensional traffic noise impacts on green space restorative effects, offering scientific support for urban noise management and green space soundscape optimization.