Acoustic Waves at Very Low Frequency: Propagation and Building Insulation

Acoustic waves at very low frequencies (straddling infrasound and sound) are produced by various sources, including wind turbines. These waves, with frequencies even below 20 Hz, can propagate over long distances and easily penetrate buildings. Wind turbines generate infrasound primarily due to the movement of the blades and mechanical components. The acoustic insulation of building facades is crucial to reduce the impact of these waves. Materials such as laminated glass, multilayer walls, and sound-absorbing panels can improve acoustic insulation by attenuating vibrations and reducing the noise perceived inside buildings. However, the effectiveness of the insulation depends on the correct design and installation of the materials, as well as the design data available. This work aims to review the calculation and evaluation models of this phenomenon.