Only Three Things Stop Noise
- SPACE. The more space there is, the more noise reduction there is. As an exaggeration, if you are 10 miles away, you will not hear it, except under strange circumstances.
- MASS. A six foot thick concrete wall works great!! If it is heavy, it will work well. Remember, if it does not weigh much it will not stop much.
- DAMPENING. This requires a little explanation. Like a wine glass, when you make it ring... but you can keep it quiet by holding it. You have dampened the noise by retarding the vibrations. This can be achieved in several ways.
Lead is heavy and soft; the softness makes it also dampen the noise and lead is an excellent noise stopper. Making noise transfer through different layers of material with different densities also helps dampen noise. Improperly done it can make things worse, like string holding chimes help them ring by isolating the vibration instead of dampening it.
Noise Reduction vs. Noise Absorption - Sound Proofing Principle
This is a very important principle to understand about soundproofing. There are two types of noise reduction and they are almost always confused with each other. All noise reduction and soundproofing are not alike. Noise absorption is not noise reduction.
Noise Reduction is achieved by stopping it, killing it, not letting the noise get through the wall or window. Stop the noise before it gets to you, or into the room you are in. For this you use mass and space. You can build heavy walls with large air spaces and you maximize dampening as best you can.
Noise absorption is achieved by changing the characteristic of the noise. Stop it from echoing. Stop the reverberation. Stop the noise reflections. All this involves handling the noise that is within the room. It seldom involves noise from outside the room. You have likely heard of a room as being a “live” room or a “dead” room. For this type of noise reduction or soundproofing you will use carpets, upholstered furniture, acoustical ceiling tile, soundboard or interior walls.
What works for noise absorption does not ever work for noise reduction. Yes, you heard me correctly: soundboard is useless at stopping noise. When put up with the sheetrock it is useless unless it is the outside layer and it is being used for noise absorption sound control.
Continue to Wall Soundproofing.