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"Soundproofing" that doesn't work

If you've read a lot of materials online already about what products to use in your own home – and horror stories about things that go wrong – then you probably already know some of the "solutions" that aren't effective. But I'll list a few of them here anyway. And while you're at it, here's an article on costly soundproofing mistakes that you might want to read, too.

What DOESN'T prevent outside noise from coming into your home (especially an apartment):

1) Carpets and rugs as the only solution. This adds some sound absorption in your own home (for example, it reduces the "echo" effect in a room) and absorbs some impact from shoes, feet, and furniture. I'm not saying you shouldn't use carpets: you should, especially as a consideration to your upstairs or downstairs neighbors. But carpeting alone will not undo some of the sound transmission in the framing of your home. Here's a quick overview from The Soundproofing Company that explains how noise is transmitted through a floor.

2) Egg cartons. I know -- you'll still find helpful hints and tips on soundproofing that recommend this method. But it really doesn't work for soundproofing. Again, it might reduce some "bounce" in a room if you're using that room to mic an instrument, but if you put egg cartons on your wall and think you won't hear your neighbors' music -- or they won't hear you talking -- forget it.

3) Spray foam. Maybe it's good at sealing hard-to-reach cracks, but don't spray it inside your walls for insulation – it won't stop the noise and it might be flammable, too.

4) Blown-in insulation as the only solution. Let me clarify: I think you should fill the hollow spots in your walls and ceilings with a sound-dampening material like fiberglass batts, cellulose, rock wool, or recycled cotton batts. It's just that doing this alone won't address all the noise issues in your home. It does dampen some resonance and muffle voices. But a lot of your noise may be impact or vibration noise that's getting transferred through the framing of your home. Putting material into the hollow spaces doesn't interrupt the transmission of this noise from one piece of wood to the next. I think it's a good idea to fill the hollows and also to stop the transmission through the framing, as well...if you can. You need both.

5) More wood. Wood-against-wood transmits noise. (Think about pianos, guitars, etc.) Be sure that if you want to add more "mass" to your walls, floors, and structure, that you use sound dampening materials and not wood, particle board, or other materials that might resonate.

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