Noise Reduction Coefficient (NRC): NRC is a ranking procedure that measures how well a cloth absorbs sound waves. The upper the NRC score, the more sound the material will take up. NRC is important for reducing noise reverberation in rooms. Felt underlayment is actually a form of padding which is https://ermaghuk81234.blogsidea.com/32928789/soundproofing-materials-for-windows-options