The paper predicted the sound reduction indices (SRIs) of plenum windows with various configurations by the surface impedance approach (SIA). Assuming that the glass panes of plenum windows are rigid, two spaces connected through a plenum window can be taken as a three-coupled space. In terms of a multiply connected space, the SIA enables to characterize the acoustical properties of each sub-space by its own descriptors – blocked pressure and surface impedance across the coupling interface surface between any two sub-spaces. With the descriptors identified, the sound radiation in the entire space can be predicted accordingly. The sound radiation due to a point source in an acoustical space consisting of a rectangular space, a plenum window and a semi-free space was successfully predicted by the approach. Providing the diffuse sound field is generated in the rectangular space, the SRIs of plenum windows could be determined with the predicted averaged sound pressure level in the diffuse source space and the predicted sound intensity level across a prescribed measuring surface in the receiver space, i.e., the semi-free space according to the standard ISO 15186–1. The SRIs of five plenum windows were studied by the SIA. The predicted results are in good agreement with the measured ones obtained in the laboratory environment, which indicates the feasibility of the SRI prediction by the SIA.

本文通过表面阻抗法（SIA）预测了具有各种配置的通风窗的降噪指数（SRI）。假设增压通风窗的玻璃板是刚性的，则通过增压通风窗连接的两个空间可以视为三耦合空间。就多重连通空间而言，SIA可以通过其自身的描述符来描述每个子空间的声学特性-阻塞的压力和任何两个子空间之间的耦合界面上的表面阻抗。通过识别描述符，可以相应地预测整个空间中的声音辐射。该方法成功地预测了在由矩形空间，充气窗和半自由空间组成的声学空间中由于点源而产生的声音辐射。假设在矩形空间中产生了扩散声场，则可以用扩散源空间中的预测平均声压级和接收器空间中指定测量表面上的预测声强级来确定充气窗的SRI。根据ISO 15186-1标准的半自由空间。SIA研究了五个通风窗的SRI。预测结果与在实验室环境中获得的测量结果吻合良好，这表明SIA进行SRI预测的可行性。根据ISO 15186-1标准的半自由空间。SIA研究了五个通风窗的SRI。预测结果与在实验室环境中获得的测量结果吻合良好，这表明SIA进行SRI预测的可行性。根据ISO 15186-1标准的半自由空间。SIA研究了五个通风窗的SRI。预测结果与在实验室环境中获得的测量结果吻合良好，这表明SIA进行SRI预测的可行性。