Research On Methods Of Improving The Validity Of Acoustical Simulation

Acoustic simulation softwares appear in the20th century, acoustical objective prediction of auditorium become possible, it cause a revolutionary significance in the acoustic design. And as the development of acoustic softwars, some more reliable acoustic simulation softwares appear, they proform well in the international round robin on room acoustical computer simulations. However in the practical projects, predictions turn out to be variable and the reliability can not be guaranteed because of the different ways of using the softwares, for example inaccurate acoustic models, unreasonable parameters, uncertainty of absorption coefficients and scatter coefficients, and so on. Therefore acoustic simulation software is not only a simple calculation tool, the realiable of prediction is to a great extent depend on the acoustic knowledge and engineering experience of users. Because of the great need in practical engineering design, the accuracy and reliability of acoustical precdition has always been paid attention to. How to improve the reliability of the simulation results has become a hot research. At present, people have made many valuable research results in the aspects of the value selections of absorption coefficient and scattering coefficient, sound source directivity and auralisation. However, in order to ensure the stability and reliability of the prediction, a lot of more research work is still need to do.As there is much uncertainty in the current acoustic simulation result, This paper studies the method of how to improve the validity of sound simulation from the following aspects:1. In the acustic model aspect, take ODEON software as example, comparied different modeling detail level and different modeling method for various holls. In order to find the modeling method which can achive the highest precition result.2. Scattering coefficient, sound absorption coefficient values has complex affecting for simulation results, especially the scattering coefficient has a great impact on simulation results. Based on a brief introduce of the difference between ODEON9.0simulation algorithm and the previous versions, simulate several holls using different scattering coefficients, then abtain a conclusion that a reasonable scattering coefficient can lead to a reliable result. Discussed the relationship between modeling detail level and T30and C80results. Find out the rule of selecting scattering coefficient values corresponding to different detail level models, proved a theoretical basis for selecting scattering coefficient. 3. In the absorption coefficient values selecting aspect, discussed the reverberation chamber measured absorption coefficient correction method and verified its effectiveness.4. In the sound directivity aspect, study the impact which sound directivity and receiver positions to simulation results in different holls of different acustic enverment.From the above aspects, improving the validity of acoustic simulation method is obtained. To test its validity, the conclusions of this study were applied to practical projects. By simulating and analyzing several representative projects using reasonable simulation method we abtained very accurate simulation results, which proved the methods of improving the validity of acoustical simulated design.