Sound Insulation Performance of Multi-Layer Membrane-Type Acoustic Metamaterials Based on Orthogonal Experiments

Abstract Fundamental limitations in low-frequency bandwidth and impedance matching continue to constrain the sound insulation performance of acoustic metamaterials. In this work, a three-layer membrane-type acoustic metamaterial (MAM) is introduced as a potential solution. Through orthogonal experiments, remarkable sound insulation capabilities are demonstrated within the frequency range of 100–1200 Hz. By analyzing the eigenmodes and sound transmission loss (STL) at resonance and anti-resonance frequencies, the underlying sound insulation mechanism of the three-layer MAM is clarified. In addition, an orthogonal experiment is utilized to identify the key factors affecting sound insulation performance. Using relative bandwidth as the classification criterion, the optimal combination of influencing factors is identified, leading to improved STL performance of the multi-layer MAM and broadening the sound insulation bandwidth. This work advances low-frequency insulation performance and bandwidth, simultaneously establishing a novel and practical framework for the design of sound insulation material.