Creating comfortable outdoor environments: Understanding the intricate relationship between sound, humidity, and thermal comfort

This study provides insight into the impact of interactive sound and humidity environments on outdoor thermal comfort in open spaces in cold regions. Executed in Xi'an, China, the research involved a synthesis of questionnaire-based subjective assessments and meteorological data collection. Four pivotal findings emerged from the study. Initially, environments characterized by concurrent acoustic and humid conditions demonstrated a proportional increase in Thermal Sensation Vote (TSV) corresponding to rising humidity levels. Secondly, in these environments, an increase in sound levels was linked to an escalated thermal sensitivity among individuals, with the most significant sensitivity, quantified at 0.1769, observed at sound intensities between 60 dB (A) and 80 dB (A). Thirdly, the influence of ambient sound on TSV and Thermal Comfort Vote (TCV) was observed to vary with ambient humidity. Variations in sound levels had a pronounced effect on both TSV and TCV within a humidity range of 25% RH to 70% RH, but this correlation dissipated in higher humidity conditions (70% RH to 85% RH). Finally, the study indicates that environments with lower sound levels contribute to the mitigation of extreme thermal stress, particularly when ambient humidity is maintained between 25% RH and 70% RH.