Research On Acoustic Environment Of Geriatric Psychiatry And Restoration Effect Of Soundscape On Dementia Patients

With the acceleration of the aging society in China,the number of Alzheimer’s patients is also increasing.The Geriatric Psychiatry provides important health care and healing services for the patients with dementia.Many studies have shown that different types of sound in the acoustic environment of the geriatric psychiatry have different effects on the healing process of dementia patients.On the one hand,various kinds of noise not only affect the sleep quality of dementia patients,but also reduce the acoustic satisfaction of patients and lead to extreme emotions and behaviors in the daytime.However,the current research on noise mostly focuses on the measurement of the type of sound source and the sound pressure level.On the other hand,the natural sound such as bird and water sound have the restorative effect on relieving stress of the ordinary people,but there are still few studies exploring the potential healing effect of them on dementia patients.In this study,a geriatric psychiatry of the hospital in Chongqing was selected as the research area to investigate the spatial temporal characteristics of noise sources and its related behaviors,the feature of the perceived understanding of dementia patients on nature sound and music and the effect of combination of nature sound and music intervention on the neuropsychiatric symptoms of dementia patients throughout 24h in-situ measurements,observation and recording of noise sources,semi-structure interview and randomized control trail respectively.It provides a theoretical basis for the noise reduction and soundscape design of the acoustic environment of the geriatric psychiatry.Throughout the 24h in-situ measurement,it indicates that the maximum L_Aeq,30minof public space at daytime showed at 11:30 a.m.or 6:30 p.m.when patients gathered for meal or medicine and it reached 73.8d BA.During this period,the maximum frequency of speaking sound was 12 times/hour.In the ward area,the acoustic environment of the ward near the atrium or the public space was quite affected by noise where the L_Aeq,30minreached maximumly at 71.3d BA around 9:00-10:00a.m.Besides,the maximum L_Aeq,30minof the ward at night was 65.4d BA around 8:00p.m.-12:00p.m.Moreover,the noise sources affecting the ward area at night included footsteps（from the corridor near the ward）,howling（the patient inside the ward）and mechanical sounds（nurses healing the patient）,which happened at 5.0 times/hour,4.75 times/hour and 3.7 times/hour,respectively.As the result of the interview of the dementia patients after hearing the nature sound and music,it suggested that the perceived understanding of the patient on the above sound depended on the feature of the sound source and background factors of patients such as their own experiences.For natural sounds,affected by the patient’s life experience,the rhythmic,single bird and water sounds that matched the daily occurrence time reminded patients of natural environment like mountains and lakes,which made them feel comfortable and calm.For music,the clarity and rhythm of music and patient’s memory of music at a young age affected their recognition and interaction with music.Among them,revolutionary songs were easy to arouse the patients’memory and made them feel excited,while the love songs made them feel peaceful.The result of randomized control trail revealed that the combination of four-tone cuckoo,cuckoo,oriole,white-eared thrush,starling,"The golden mountain in Beijing","Sunrise at east","Three Disciplines and Eight Items","The Soldier","Sweet Honey",and the"The Moon Represents My Heart"was accepted by dementia patients and they insisted on completing the intervention.The results showed that the severity and frequency of delusions,aggressive behaviors,irritability/mood instability symptoms in patients were significantly decreased after the intervention（p<0.01）.At the same time,the anxiety of caring the above symptoms by caregivers was also decreased significantly（p<0.01）,and the patients tried to cooperate with the caregivers more.Although the growth rate of Aβamyloid protein did not decrease significantly after the intervention（p>0.05）,the rate of it still decreased by 29%.In addition,with the intervention going on,the patient’s willing for participation and interaction gradually increased.The positive behaviors such as singing,clapping,nodding,and raising their hands occurred during the intervention as well.Taking the geriatric psychiatry as an example,this study attempts to explore the healing effect of natural sounds on dementia patients and analyze the spatial and temporal characteristics of noise sources.This has practical significance for creating a quiet acoustic environment for the dementia patients,and designing a low-cost,low-invasive soundscape intervention to assist the healing and rehabilitating process of dementia patients.At the same time,it also has reference significance for the noise reduction and soundscape design of other dementia care and treatment institutions.