Theoretical Study And Design Of A Combined Auralization And Visualization System For En-closed Sound Fields

Combined auralization and visualization is a new technique in modeling enclosed sound fields,which is based on the technique of parameter prediction,visualization and auralization. By using such a technique an acoustic consultant can control the sound quality of an enclosed filed from not only the objective indexes,but also the impression of hearing and vision. Therefore,it can be applied into the fields of auditoria acoustic design,noise control,virtual reality,and so on.In this work the major aspects of the technique of combined auralization and visualization have been investigated,including the basic concepts,status of development,theoretic basis,algorithm design and validation,applications and its future development. A combined auralization and visualization system,CAVS,designed by the author has also been described. The main ideas of this dissertation are as follows.First,the basic concepts and the status of development have been reviewed and then an overview has been taken on several current computer models. Based on these,an improved ray-tracing algorithm has been developed,in which a dynamic receiving method has been implemented to overcome the errors due to the systematic detection problem. The algorithm has taken into account both specular and diffuse reflections under the condition of broadband sound inputs. Based on the algorithm,the modeling methods of complex situations such as curved surfaces,partial absorption,directional sources,multiple sources and various sound barriers,have been presented. Then,the objective modeling (parameter prediction) and the subjective modeling (binaural auralization) of enclosed sound fields have been studied in detail. In order to verify the above algorithms,the results worked out by our computer program have been compared with those of measurement in real buildings,calculating by statistical method,modeling by other researchers and a kindred software. All these experimental works have shown that our programs are correct and feasible. Then,the principle and functions of the computer system CAVS (Combined Auralization and Visualization System),which was designed by the author has been briefly described. Finally,the problems to be solved have been concluded and the further developments have been discussed.