Effects of indoor acoustic and olfactory environment in nursing homes on the perception of the older adults

Abstract Objective: To investigate how combined auditory and olfactory environments influence older residents’ perception, emotional state, and behavior in nursing homes. Methods: Field measurements and subjective evaluations were conducted across four nursing homes in China, including sound pressure level monitoring, controlled exposure to five sound types and four scent types, and behavioral observation. Results: Sound levels were lower in residential units but exhibited fluctuations in activity areas. Olfactory satisfaction was higher in public spaces, with bathroom odors identified as a primary stressor. Preferences varied spatially: activity areas favored mint and citrus scents paired with natural sounds, whereas residential units preferred lavender and sandalwood with calm auditory stimuli. Combined auditory-olfactory stimuli yielded significantly better outcomes than single-modality conditions. Conclusion: Multi-sensory design, tailored to spatial function, can enhance well-being among older residents. Practical strategies include sensory zoning, improved acoustic conditions, and adaptive scent delivery systems.