A: Panels are rated in NRC (Noise Reduction Coefficient) and our bass traps in Sabins (device of evaluate of sound absorption inside the inch-pound program). All of bass traps and panels are independently analyzed by Riverbank Acoustics. The upper the absorption # the better the panel is. Lola Houlton https://israelznwel.bloguetechno.com/how-much-you-need-to-expect-you-ll-pay-for-a-good-noise-reduction-69850580