Research On The Sound Environment Of University Library

The university library not only has the functions of collecting,sorting,saving,borrowing and providing information retrieval of the ordinary library,but also is the main place to study and research for the teachers and students in colleges and universities,and it also provides the users with atmosphere and space for academic exchange,discussion,exchange of ideological information and holding a number of social activities.The former requires the library to have a quiet sound environment so that users can study and think deeply.The latter needs more open space so that more work can be done in the form of groups.So,computer,multimedia and other facilities will be required,and more noise will be produced.All these make the sound environment of the university library unprecedented complex.A questionnaire survey and objective acoustic parameters measurement were carried out on the sound environment of university library.So the noise sources of the library and the disturbing extents to the students were learned and understood.The noise control strategies of the whole construction process were discussed,including case study,experiments,simulation and prediction,calculation and so on.Users' evaluation on acoustic comfort is influenced not only by objective acoustic parameters,but also by many other non acoustic factors.So the other influence factors of sound environment were analyzed,which included physical environment,individual factors,landscape and architectural features and so on,and the indoor and external sound landscape models of university library were set up.In the discussion of the noise control strategies in the whole construction process,the sound isolation of light walls,doors and windows,as well as vibration isolation of the floor slab were tested,simulated and calculated.The sound insulation properties of light walls with different surface density follow the mass law,that is the larger the surface density is,and the better the sound insulation effect is.But after plastering,within limits,no matter one side plastering or double plastering,the difference of sound insulation properties among light walls with different surface density is very small,that is,which is the influence of surface density on sound insulation is weakened.The study shows that the improvement on sound insulation properties of the plastering for the light walls is mainly decided by the sealing effect on the surface rather than mass,because the thickness and mass of the plastering layer is too small.The outdoor space of university library is the continuation of interior space.The research on the sound comfort of outdoor space of library was done,which indicated that subjective sound comfort evaluation was influenced by the source types and sound pressure level(SPL).For the sound environment dominated by the natural sound,the subjective sound comfort evaluation is less affected by the change of SPL.For the artificial sound environment of people like,the subjective evaluation is less influenced by the change of SPL when it is within a certain threshold,but the disturbing will be caused if the SPL exceeded the threshold.And for the sound environment of people dislikes,there is a strong correlation between SPL and subjective sound comfort evaluation.People have a higher preference for quiet sound environment,and for a sound environment with a comfortable background sound,the choice of preference is more diversified.This result is not consistent with the literature of other spaces? investigations.The reason is different users and space functions.Sound pressure level,air quality,temperature,illumination,wind speed and humidity are the main factors that affect the overall evaluation of comfort but only 52.9%,and there are other factors that will affect the overall evaluation.Based on the research of sound comfort degree,the library indoor and outdoor soundscape models are built.In this paper,the relationship among the indoor acoustic environment,architectural characteristics and individual factors was analyzed.The dependencies of physical and psychoacoustical factors of the sound environment and the architecture factors were statistically tested,and the results show that the effect of human flow rate on the SPL and loudness is significant.At the same time,the time factors,spatial factors and the interactions of the two factors have significant influence on the SPL and loudness.This paper has done a series of research on the university library,which has a certain reference value and guiding significanceMany studies have been done on the sound environment of university library,which have a certain reference value and guiding significance for the research and design of other types of buildings,such as libraries,educational buildings,office buildings and so on.