sound permeability symbol

sound permeability, acoustic permeability, sound transmission, acoustic transmission, noise transmission, sound absorption, acoustic absorption, sound insulation, acoustic insulation, noise reduction, sound attenuation, acoustic attenuation, sound diffusion, acoustic diffusion, sound barrier, acoustic barrier, noise control, sound isolation, acoustic isolation, sound leakage, acoustic leakage, noise leakage, sound penetration, acoustic penetration, sound transparency, acoustic transparency, material porosity, acoustic porosity, sound damping, acoustic damping, sound waves, acoustic waves, noise propagation, sound propagation, acoustic propagation, building acoustics, room acoustics, wall acoustics, ceiling acoustics, architectural acoustics