Research On Acoustic Environment Of Enclosed Courtyard In Changchun Universities

Courtyard space in university is an inward,independent and open space that is closely related to surrounding buildings.By far,no researches of acoustic environment of university courtyard have been reported.In this paper,the acoustic environments of two typical courtyards in a university in the city of Changchun,China,are studied on the grounds of both the measurement of acoustic parameters and the survey of users' subjective assessments.To be specific,the measurement of acoustic parameters is used to figure out characteristics of the sound pressure level and the sound field distribution in the two courtyards.The questionnaire survey is used to obtain general characteristics of sound perception and activity type as well as to collect subjective assessments on the optimization of environmental elements.In addition,the ODEON acoustic parameters are applied to simulate and investigate sound absorption of different green walls and layout forms.The study results show that: the two courtyards are different in both the sound pressure level and the sound field distribution,and the assessed sound pressure level in the teaching courtyard is much higher than that in the living courtyard.The subjective assessments suggest that activity types and frequencies in different functional courtyards are different.For improving acoustic environments of the courtyards: the teaching courtyard shall be relatively quiet under natural sounds,while the living courtyard shall be filled with some daily sounds in addition to natural sounds.Through the acoustic simulation we find that: the wall covered with greenery in point-mode has the highest capability of sound absorption,followed by the curve-mode,and the plane-mode has the lowest capability;and,with increasing the greenery coverage on the wall,the capability of sound absorption increases at first and then decreases.