在脉冲响应频率分析比较中对客观声学参数EDT的新认识(英文)

New Developments About the Objective Parameter EDT in Comparison with the Frequency Analysis of the Impulse Response

对于客观参量EDT,或者更确切地说,对于稳态声场衰变曲线的初始斜率与包括所有简正模式在内的平均阻尼常数之间关系的研究工作,已有一些研究者做过,如H.库特鲁夫就曾指出此参量与所测试环境的几何细节有密切关系.因此,文中选择它作为分析工具,以一种较为深入的方式,通过对一个歌剧院的研究,来检验这种关系.通过对脉冲响应在频域上进行分析,这在前人的工作中也采用过.文中对EDT从倍频程以及1/3倍频程加以研究,并利用在Matlab环境下开发的一些工具来探讨乐池的简正模式与从频带中心频率导出的最大的时间值之间的相关关系.研究表明,在所考察的环境中简正模式与衰变曲线的初始斜率之间有良好的相关关系,与自相关系数(ACF)也有良好的相关关系;研究还证实,用于分析的参量本身既是时间的函数,也是脉冲响应频率变化的函数.

The objective parameter EDT, and more precisely, the correlation between the initial slope of the decay curve of the stationary field and the average damping constant of all excited normal modes, has been studied by some author, i.e.H. Kuttrufl＇, who affirms, besides, that such parameter is very close to the geometry details of the envirunment under test. Therefore, it has been chosen to make an analysis in a deeper way to verify such condition through the study of an opera house, by means of the analysis in the frequency domain of the impulse response that has been already verified in various furegoing reports. The EDT parameter has been studied both in octave band and in 1/3 octave band, and, by using some tools developed for this work in Matlab environment, it has been possible to verify the correlation between the normal modes of the orchestra pit and the highest temporal values traceable to the central band frequencies, the relatives buth to the octave band and the 1/3 octave band of the parameter examined. The results demonstrate the good correlation between the initial slope of the decay curve and the normal modes of the environment under test, also with the application of the autucurrelatiun function （ACF）, confirming, moreover the good choice of the applied criteria fur the analysis, in function of the time, of the frequency changes of the impulse response.