Research On Physiological Effects Of Soundscape In Urban Public Open Spaces

A healthy living environment is the common pursuit of individuals and society,in which the acoustic environment is closely related to human life,and has a great impact on human beings in terms of physiology,psychology and behaviours.With the developping of the research in the field of soundscape,simply considering the noisy degree of sound is no longer enough to describe all the characteristics of sound.The study of soundscape needs to consider not only the influence of negative sound sources,but also consider the positive effects of sound on people.Exploring the influence of soundscape on human physiology is not only the bridge between soundscape and health,but also the way to realize healthy sound environment.This study took the physiological indicators as the observation means to explore the influence of the typical soundscape factors on the human physiology in the urban public open spaces,and combined with the subjective questionnaire survey,to analyze the relationship and difference between objective physiological indicators and subjective evaluation factors.This study studied the existing soundscape theory and the basic theory of electrophysiology,and the common classification methods and characteristics of soundscape were discussed.The soundscape classification standards were determined according to four categories: biological sound,geophysical sound,human sound and mechanical sound.Through interviews and analysis of previous literature,screened out 20 typical soundscapes in the city public open spaces,and also screened out the physiological indicators involved in the experiment,including ECG,EEG,respiratory wave,body temperature and SCL.This study studied and designed the test methods of soundscape physiological experiments in the laboratory,and discussed the method of recording and reproducting of soundscape,the processing method of soundscape stimulation fragments,as well as the instruments and experimental sites of the experiments,which provides a research paradigm for the physiological research of soundscape in the laboratory in the future.From the view of exposure time,the sensitivity of physiological indicators in soundscape was studied.The repeated measurement analysis of variance was carried out on the physiological data in four time periods,and the effects of time and sound type on the physiological indicators were analyzed.Six subjective restorative factors were obtained by reducing the dimension of the PRSS scale.Canonical correlation analysis was used to study the relationship between physiological indicators and subjective evaluation factors in four time periods,and the most suitable time to record human physiological indicators in soundscape was obtained.The audio-visual interaction in soundscape was studied.By controlling vision and hearing,four presentation modes of soundscape were designed: video + sound,image + sound,pure video and pure sound.By comparing the differences between video + sound group and image + sound group,the effects of dynamic vision and static vision on physiological indicators and subjective evaluation were studied.By comparing the differences between pure video group,pure sound group and video +sound group,the influence of visual factors in soundscape on auditory factors,and the influence of auditory factors on visual factors were studied.By comparing the differences of physiological indicators under different presentation modes,this study could provide some suggestions on the audio-visual restorative method of soundscape and the construction method of restorative space in the future.The changes of sound source distance and attenuation mode in soundscape were studied,and the soundscape stimuli with different sound source distance were obtained by recording short-distance and long-distance sounds at the same time.Through the equivalent sound pressure level compression of short-distance sound,the stimuli with different attenuation modes were obtained.By comparing the difference between the actual close sounds and the actual distant sounds,the influence of sound source distance on physiological indicators and subjective factors were analyzed.By comparing the difference between artificial distant sounds and actual distant sounds,the influence of attenuation mode on physiological indicators and subjective factors was analyzed.By comparing the differences of physiological indicators in different distance modes,this study could provide some suggestions on the control of noise sources and the playback of soundscape stimuli in the laboratory in the future.The physiological indicators of 20 kinds of typical soundscape in urban public open space were studied,and the effects of soundscape categories on physiological indicators and subjective evaluation factors were studied.Using CATPCA method,the dimension of physiological indicators and subjective factors were reduced,twodimensional physiological indicator model and subjective factor model were got,and the distribution of different kinds of soundscape in the two models were analyzed,which could provide a new direction for the perception of soundscape.The objective acoustic parameters in the soundscape stimuli were calculated,and the correlation between the acoustic parameters and physiological indicators was studied.Through the construction of linear regression model,the trends of physiological indicators affected by acoustic parameters was analyzed.It is possible to further predict the physiological response of people in soundscape by acoustic parameters.The innovations of this study include: exploring the sensitivity of physiological indicators in soundscape;studying the physiological perception differences of audiovisual interaction;studying the effects of sound source distance and attenuation mode on physiology;and exploring the relationship between physiological indicators and subjective evaluation as well as objective acoustic parameters.This study is helpful to further explore the relationship between soundscape quality and health,and could provide new methods for urban soundscape evaluation,as well as provide a theoretical basis for the design of "restorative soundscape".