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Showing posts with the label noise transmission

Why a decoupled ceiling might not eliminate all noise

A decoupled ceiling might eliminate most of the noise between floors, but not all of it.   If you're thinking of decoupling a ceiling in your home or apartment, you might not eliminate all the noise between two floors. This doesn't mean that it's not worth doing. It means that resolving noise issues in your home might be an iterative process. Because after you address one noise source, you might discover another one. Noise paths A noise path is how a noise enters another space. For example, this could be through the air or through a thin wall, through the joists and studs in a building frame, through a wall outlet, or through a vent. You might soundproof one noise source only to realize afterwards that there were other points of entry for that noise. So if you're thinking about removing your existing ceiling and decoupling it with soundproofing materials, keep in mind that some types of noise might be coming from different sources via different paths. You might reduce o

Blow-in cellulose and your hollow walls

It's not too late to insulate.  A few years ago, most American homes had no insulation in them. When a homeowner did insulate, it was usually with fiberglass batts. Then along came some better products. One of them is blow-in cellulose insulation. Does it work? I can attest to this: YES. I've used it in walls and ceilings, and it works quite well for airborne noise. If you live in an uninsulated home and you hear your neighbors voices coming through your walls or ceilings, cellulose will dampen that noise or mute it entirely. It doesn't work for all types of noise. But it doesn't eradicate impact noise. You might still hear the sounds of someone walking across a bare hardwood floor with their shoes on, for example, or hear wall-mounted cabinets opening and closing. There are other solutions for that, and by combining different solutions you can control most structural noise and create more privacy. Low cost Blow-in insulation is inexpensive. You can hire a

Mass is not enough

Can you block noise by adding mass? That depends on the situation. What kind of noise? How does the noise travel? What materials will you use, and how will you apply them? This 2008 article from " Sound on Sound ," explains that sound "cannot be destroyed: it can only be converted into another form of energy." While some sounds are airborne and can easily be blocked, you might still hear lower-frequency sounds passing through on the other side. This is because the energy from sound waves makes the walls vibrate, and this creates more energy. Does adding mass help? Yes. Will mass solve all your noise issues? Possibly not. You might also need to address other characteristics of the space by adding sound absorption inside the rooms, or by decoupling the floors, ceilings, or walls from the structure to keep the sound (energy) from passing into it. Let's look at a couple of examples. Example 1: Interior doors Many American homes feature hollow-core interi

Example: how wood turns vibration into noise

When noise becomes a low frequency vibration... I made this short video with my mobile phone to show how an airborne noise (the buzz from my mobile phone when it's set to "vibrate") becomes a loud, intrusive noise when it makes direct contact with a wood surface. This is the same way that simple impact noises like walking, opening and closing doors and drawers, or even the bass from your stereo or home theatre system can go into the walls and transmit to your neighbors or to other rooms in your home. I placed different materials underneath the phone while it was buzzing on top of the wood table. You can hear how each of them (even the thin sheet of cork) make a difference in reducing the noise transmission through the wood. One point: while I was recording this, I noticed that QuietRock (being the "hardest" of the surfaces) still transmitted a tiny bit of vibration to the wood beneath it, while at the same time dampening the buzz. That's an example of

A simple lesson about how sound bounces

Create an angle to reduce the "bounce" This short video from eHow  / ExpertVillage Leaf Group shows how to build an effective, soundproof window in a recording studio. You'll learn how angling a surface (rather than using straight, 90-degree connections) helps to reduce sound transmission. Notice how the glass for this studio window is inserted at a slight angle. This is a terrific lesson on sound transmission.