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封闭声场视听一体化系统理论研究与系统设计

Theoretical Study and Design of a Combined Auralization and Visualization System for En-closed Sound Fields

【作者】 曾向阳

【导师】 孙进才;

【作者基本信息】 西北工业大学 , 水声工程, 2002, 博士

【摘要】 声场视听一体化是在封闭声场参数预测(Parameter Prediction)、可听化(Auralization)和可视化(Visualization)基础上提出的一个新的概念,其本质含义是:在一定的声学、数学和信号处理理论基础上,通过建立三维声场的计算机模型,实现从客观声学指标、主观听觉感受和直观视觉效果三方面对三维封闭声场进行综合的预测和评价。该技术为建筑音质设计、噪声控制和虚拟现实等领域开辟了新的研究方向,具有很高的理论价值和实用价值。 本论文围绕视听一体化这一新的声学研究方向,在国内首次系统、深入地研究了视听一体化理论和实现方法,并进行了大量的实践研究。论文内容涵盖了声场视听一体化的基本概念、发展状况、理论基础、实验论证、实现方案、应用前景、发展趋势等各个方面,并对自行研制的视听一体化系统CAVS作了介绍。 论文首先简要介绍了封闭声场模拟的基本概念和研究意义,回顾了该领域的发展状况;然后提出了一种基于线性滤波的封闭声场建模思想,并在对现有方法进行综述和比较的基础上,提出了一种适合于宽频带条件的改进声线跟踪法;利用以该方法为核心的混合方法研究了指向性声源、组合声源、弹性结构声辐射、曲面墙壁、弹性界面、局部声吸收以及存在不同声障碍物等复杂声场条件下的模拟理论;在上述工作的基础上,研究了封闭声场音质的客观模拟(参数预测)和主观模拟(双耳可听化,Binaural Auralization),推导了与宽带动态声接收方法相对应的常用声学参数的计算机模拟方法,探讨了双耳可听化中脉冲响应后处理、相位补偿方法等关键性问题;经计算机模拟,其结果与同行的研究结果、同类软件的计算结果以及实验室和普通房间的实测结果作了对比研究,分别从客观音质参数和主观听音效果两方面验证了本文算法的正确性和可行性;然后,给出了一种封闭声场视听一体化系统的基本结构,并介绍了自行研制的视听一体化系统CAVS的原理、功能和操作方法等;最后,总结了封闭声场视听一体化模拟研究中目前存在的主要问题,并指出了进一步发展的方向。

【Abstract】 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.

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