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 4 nursing homes in China, including sound pressure level monitoring, controlled exposure to 5 sound types and 4 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. Conclusions: 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.