The multisensory environmental evaluations of sound and odour in urban public open spaces

Few studies have focused on the multisensory perception of audio–olfactory interaction with the purpose of improving the use of urban spaces. This study conducted multisensory environmental evaluations in three urban open spaces in China with the aim of verifying the existence of audio–olfactory interaction in the urban environments and providing different perspectives for the improvement of urban environmental quality. A sensewalk approach was adopted in the study, and the main research contents were: the odour’s effects on sound source and sound environment evaluations, and the sound’s effects on odour source and odour environment evaluations. The results indicated that food odour improved acoustic comfort and sound congruency and reduced subjective loudness. Pollution odour worsened the assessment of traffic and lowered subjective loudness. Sound decreased the subjective intensity of odour and exacerbated its evaluation. Additionally, food odour enhanced the sound environment assessment of pedestrian streets, while pollution odour worsened it. Sound had a weak impact on odour environment evaluations. The masking effect between sound and odour showed that the presence of the latter decreased subjective loudness while increased sound diminished the subjective intensity of odour. Furthermore, odour’s influence on sound evaluations was greater than the influence of sound on odour evaluations. These findings have implications for the planning and design of a livable and comfortable urban environment through the perspective of sensory interaction.