| University lecture hall is an important place for academic exchange,report meeting and study seminar.It is not only a bridge between disciplines and departments to communicate and learn from each other,but also an important window for universities to contact with the outside world.Therefore,it has high requirements for sound quality design.In this paper,the university lecture hall as the main research object,through on-site investigation,mapping,combined with the questionnaire survey found that the university lecture hall at present there are too long reverberation time,low language clarity.In addition,after literature review of university lecture halls,it is found that there is a lack of systematic research on sound quality optimization design strategies and comprehensive evaluation.This paper will improve relevant research:First of all,the relevant evaluation indexes of university lecture halls are sorted out,including reverberation time（RT）,background noise（NBL）,speech clarity index(STI,D50,ALcons%),sound field nonuniformity（（35）Lp）and loudness index（G）,etc.,and the relevant measurement standards and standard requirements are elaborated.Secondly,a single evaluation index is selected from the evaluation parameters of the university lecture hall to verify the non-correlation between each index.The weight of each index is obtained through analytic hierarchy process,and the optimal range of each parameter is determined,and the comprehensive index is proposed to evaluate the sound quality effect of the university lecture hall.Thirdly,on the basis of the research on university lecture halls,it is divided into three common acoustic types:rectangle,fan-shaped and circular,and various typical lecture halls are selected for measurement and subjective questionnaire analysis.On the one hand,the measured results reveal that there are big problems in the overall architectural acoustic design of various university lecture halls when the sound amplification system is not used,which lays a foundation for the later optimization.On the other hand,based on the measured data and questionnaire results,the rationality and feasibility of the comprehensive evaluation index are confirmed,and the grade of the comprehensive evaluation index is as follows:0～0.5（bad）;0.5～0.65（poor）;0.65～0.8（good）;0.8～1（excellent）.Finally,the ODEON acoustic model of each lecture hall is established respectively.On this basis,the optimization design is analyzed,and the comprehensive evaluation index is used to evaluate the sound quality effect after optimization,again verifying the rationality of the comprehensive evaluation index and the feasibility of the optimization scheme.In view of the common acoustic problems of various university lecture halls,the corresponding optimization design strategies are put forward.In addition,combined with the proposed optimization design strategy of the university lecture hall,a case design of the sound quality of the university lecture hall is carried out to verify the effectiveness and feasibility of the design optimization strategy.Finally,the odeon acoustic model of each lecture hall is established respectively.On this basis,the optimization design is analyzed,and the comprehensive evaluation index is used to evaluate the sound quality effect after optimization,again verifying the rationality of the comprehensive evaluation index and the feasibility of the optimization scheme.In view of the common acoustic problems of various university lecture halls,the corresponding optimization design strategies are put forward.In addition,combined with the proposed optimization design strategy of the university lecture hall,a case design of the sound quality of the university lecture hall is carried out to verify the effectiveness and feasibility of the design optimization strategy.The comprehensive evaluation index and optimization design strategy proposed in this paper can provide ideas for the sound quality design and optimization of the university lecture hall,which has a certain practical significance. |
