Sounds in nursing homes and their effect on health in dementia: a systematic review.

Objectives: Nursing home residents with dementia are sensitive to detrimental auditory environments. This paper presents the first literature review of empirical research investigating (1) the (perceived) intensity and sources of sounds in nursing homes, and (2) the influence of sounds on health of residents with dementia and staff.

Design: A systematic review was conducted in PubMed, Web of Science and Scopus. Study quality was assessed with the Mixed Methods Appraisal Tool. We used a narrative approach to present the results.

Results: We included 35 studies. Nine studies investigated sound intensity and reported high noise intensity with an average of 55-68 dB(A) (during daytime). In four studies about sound sources, human voices and electronic devices were the most dominant sources. Five cross-sectional studies focused on music interventions and reported positives effects on agitated behaviors. Four randomized controlled trials tested noise reduction as part of an intervention. In two studies, high-intensity sounds were associated with decreased nighttime sleep and increased agitation. The third study found an association between music and less agitation compared to other stimuli. The fourth study did not find an effect of noise on agitation. Two studies reported that a noisy environment had negative effects on staff.

Conclusions: The need for appropriate auditory environments that are responsive to residents' cognitive abilities and functioning is not yet recognized widely. Future research needs to place greater emphasis on intervention-based and longitudinal study design.