The best way to prevent a noise problem is to construct the room with building materials and techniques that will reduce the noise that enters or leaves a room. Pre-planning in this way is not always possible, however, especially for renters. In those cases, soundproofing a room centers on how to absorb unwanted noise after the walls already are in place.
Soundproofing Walls
If you are building the walls or are willing to re-do existing walls, consider using two layers of sheetrock with a small amount of space in between. They can be glued together using a layer of silicone or a special type of sound-dampening glue. For existing walls, a layer of sheetrock can be added over the wall. Sounds waves are reduced as they travel through mass and as they go from substances of different densities, which is why two layers of sheetrock that are slightly separated are better than one layer that is twice as thick. Various sound-reducing materials also can be added to the interior of walls, such as fiberglass insulation, rockwool insulation, mass-loaded vinyl or certain types of soundproofing foam panels.
Doors and Windows
Doorways and windows can also contribute to unwanted noise problems. Thick, solid doors and double- or triple-paned vinyl-framed windows will block more sound than thin doors and single-paned windows. Also, just like the way that a draft of air can travel through leaks around a door or window, sound can enter or leave a room through them. Weatherstrips or caulk can be applied to the gaps around door frames and windows to reduce the amount of sound that sneaks through the gaps.
Floors and Ceilings
Floors and ceilings can be soundproofed as well. Carpet can be installed over carpet padding on floors. Special sound-reducing mats also can be laid under the carpeting. A ceiling can be soundproofed by adding a drop ceiling, which is sometimes called a false ceiling or suspended ceiling. This type of ceiling consists of special panels hung from the ceiling.
Less-Expensive Options
If money is a concern or time is limited, a less drastic, inexpensive approach to making a room soundproof might be needed. This might include using a large bookcase or other furniture against a wall, effectively making a thicker wall through which the sound must travel, or using thick curtains over windows to help keep sounds from traveling through the window as easily. Other simple techniques that can reduce the noise in a room involve absorbing the sound that is already in the room, rather than blocking it from entering or leaving the room.
Sound-Absorbing Surfaces
Hard, smooth surfaces in a room typically do nothing to help eliminate sounds, and they might make the noise problem worse. Soft rugs, carpet and curtains can absorb sound. Rough surfaces on walls and ceilings, such as sprayed-on texture, can help reduce the sound waves in a noisy room.
Wall Treatments
Wall treatments or decorations also can help make a room soundproof. This usually involves tacking on or hanging some sort of heavy material that will block sound waves. The material can range from carpeting to blankets to manufactured paneling — even cardboard egg cartons are an option in some situations. As with most soundproofing materials, the thicker, the better.
