High sound pressure levels (SPL) pose notable risks in loud environments, particularly due to noise-induced hearing loss. Ill-fitting earplugs often lead to sound leakage, a phenomenon this study seeks to investigate. To validate our methodology, we first obtained computational and experimental acoustic transmission data for stand-alone slit resonators and orifices, for which extensive published data are readily available for comparison. We then examined the frequency-dependent acoustic power absorption coefficient and transmission loss (TL) across various leakage geometries, modeled using different orifice diameters. Experimental approaches spanned a frequency range of 1--5 kHz under SPL conditions of 120--150 dB. Key findings reveal that unsealed silicone rubber earplugs demonstrate an average TL reduction of approximately 18 dB at an overall incident SPL (OISPL) of 120 dB. Direct numerical simulations further highlight SPL-dependent acoustic dissipation mechanisms, showing the conversion of acoustic energy into vorticity in ill-fitting earplug models at an OISPL of 150 dB. These results highlight the role of earplug design for high-sound-pressure-level environments.

翻译：高声压级（SPL）在嘈杂环境中构成显著风险，特别是由于噪声引起的听力损失。不贴合的耳塞常导致声音泄漏，本研究旨在探究这一现象。为验证方法，我们首先获取了独立狭缝谐振腔和孔口的计算与实验声学传输数据，这些已有大量公开数据可供比较。随后，我们研究了不同泄漏几何结构（通过不同孔径建模）的频率相关声功率吸收系数与传输损失（TL）。实验方法覆盖了120-150 dB SPL条件下1-5 kHz的频率范围。关键发现表明，未密封的硅橡胶耳塞在120 dB总入射声压级（OISPL）下平均TL降低约18 dB。直接数值模拟进一步揭示了声压级相关的声能耗散机制，显示在150 dB OISPL下，不贴合耳塞模型中的声能会转化为涡量。这些结果凸显了耳塞设计在高声压级环境中的重要性。