耦合空间中不同衰变类型声场的边界研究

在耦合空间中,除了传统的指数衰变形式,通常还存在其它两种不同类型的声衰变方式,一种开始时衰变很快后来衰变速度降低,另一种相反,每一种衰变的形式在耦合空间中都占据一定的区域。目前的一般观点是:系统的物理边界,如两子空间之间的隔墙和耦合口,是空间中两类不同声场的边界。通过数值模拟和实验验证,发现这种物理边界划分并不能准确区分具有不同特性的声场。本文中给出了这两种不同特性声场之间的边界,发现这边界并不处在通常人们认为的隔墙之类的物理边界上,而是越过物理分隔进入相对更为活跃的子空间中。这种侵入的程度取决于两子空间自身混响之间的差异,差异愈大侵入得愈多。 

Acoustic field boundaries of coupled volumes with different energy decay styles

In coupled rooms,besides the common exponential decay,two other different decay styles can be observed sometimes.One decays fast in the beginning and slow down in the late part,while the other in the opposite manner. Each type of decay style occupies a region in coupled rooms.The popular opinion is that,two different styles of sound field are divided by the physical boundary such as the partition and coupling aperture between sub-rooms.By conducting numerical simulation and experiments,the divergence between this physical boundary and that of the sound field was found.The boundary which divides the sound field of different decay styles was provided in this article,and it is not located at the partition or coupling aperture,but infiltrate to the more ‘live’ sub-room.The degree of the infiltration depends on the dispersion of natural reverberation between the two sub-rooms,the large it is the more the infiltration appears.