Abstract: The factors influencing the active noise attenuation of a sound-insulation ventilation window were investigated experimentally. The window system was constructed by staggering the opening sashes of a spaced double glazing window to allow ventilation. Transparent microperforated absorbers (MPA) and sound-absorbing material were used along the ventilation path to attenuate external noise. The performances of the four-input and four-output active control system for the window with different secondary source locations and secondary-path modeling length were compared mutually. It is found that to achieve the considerable attenuation effect in the surface of the window, locations of the secondary sources should be so arranged that the effective scope of the secondary sound field can cover the inner space of the window and the noise energy can be reduced, or the sound field is directed to the internal window glass to directly control the radiation noise. If the optimal length of the secondary-path modeling cannot be achieved in actual application, a longer modeling length should be chosen appropriately to avoid degenerating the noise attenuation or leading the system instability.

Key words: acoustics, sound-insulation ventilation window, active noise control, secondary source location, modeling length, experimental investigation

摘要： 通过实验研究影响通风有源隔声窗降噪效果的各种因素。隔声窗为错列双层玻璃结构，内外层玻璃上交错开口以便隔声窗内外侧自然通风；玻璃间的风道内铺设吸声棉和微穿孔板吸声结构来吸收额外噪声。实验分析错列隔声窗中，四通道有源控制系统在不同次级源布放位置、不同次级通路建模长度下的降噪性能，结果表明：要使隔声窗表面都有较好降噪效果，次级声源安装位置应使次级声场作用区域尽可能覆盖隔声窗内部空间，降低隔声窗内的噪声能量；或者指向隔声窗内侧玻璃表面，直接控制透过玻璃辐射的噪声。次级通路建模时，如无法精确得到最优值时，可适当取较长的建模长度，以避免其小于最优长度导致控制效果急剧下降。

关键词: 声学, 通风隔声窗, 有源噪声控制, 次级源位置, 建模长度, 实验研究