厅堂声学计算机模型的应用(英)

此处所介绍的厅堂声学计算机模型计算了房间和多功能厅的声学响应。这个模型是以房厅的三维表示为基础的。每个墙面都赋予一个吸声系数，并且分成更小的单元。首先计算了单元间影响系数所组成的矩阵。对于给定的声源，可以计算每个单元收到的能量，并由此定出房厅内任一点的声级，这样又能够算出（ａ）随距离变化的衰减，（ｂ）在任一平面上的声照度，和（ｃ）任一点所收到声能的接收指向性．可以算出房厅内任一被选定点的回波图，作为接收器所在地接收指向性随时间的演变；这么一个特点使得有可能核对目视图象和声图象之间的可能不符。这个软件能够设法任意修改房间的形状，以最优化房间的声学特征．本文列举了一个厅堂声学的研究例，是关于沙特拉伯首都Ｒｉｙａｄｈ的 Ａｈｕｒａ主厅的。

An application of the hall acoustics computer model

The Hall Acoustics computer model presented here carries out the computation of the acoustic response of rooms and large multipurpose volumes. The model is based on the 3D representation of the volume. The surfaces are each assigned an absorption coefficient and are subdivided into smaller elements. A matrix of influence coefficients between elements is first calculated. Given a sound source, the energy received by each element is calculated, and from this, the sound level at any point in the volume can be determined, making it possible to calculate (a)the attenuation with distance, (b)the acoustic illumination on any plane, and (c)the reception directivity of the sound energy received at any given point. Echograms at any chosen point in the volume can be calculated, as well as the evolution with time of the reception directivity at the receiver: such a feature enables checking the possible discrepancy between the visual and the sound pictures. This software makes it possible to modify the shape of the room at will, in order to optimize its acoustic features. One example of hall acoustics studies is presented (Main Hall of Al Shura, Riyadh, Saudi Arabia).