When leakage dynamic pressure waves (DPWs) propagate in low Mach number flows, the viscothermal effects are considered the main reason for sound attenuation. However, an experimental analysis con-ducted in this study shows that the non-equilibrium sound-turbulence interaction process is the main cause. The turbulence effects due to turbulent flows act on the DPWs, and the fluctuations due to the DPWs act on the turbulent flows. Both processes result in the turbulent absorption of the gas to the amplitude of the DPWs, leading to amplitude attenuation at sufficiently low frequencies. To predict the amplitude attenuation, a non-equilibrium sound-turbulence interaction model is established, solved, and verified using analytical and experimental results, which show that attenuation coefficients (ACs) obtained by considering the sound-turbulence interaction effects are 1.6-3.5 times larger than those obtained by only considering the viscothermal effects, even when the Mach number is between 0.0038 and 0.016. The established model can improve leak localization. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.