‘Sound’ solutions to dampen noise in your home

If you’re sensitive to noise, there’s plenty you can do to reduce unwanted sounds.

Maybe you’re being acoustically assaulted from outside, upstairs or just the next room. I’ll give you a few strategies to reduce noise transmission, but keep in mind that sensitivity to noise is highly subjective, and the type of noise can make a big difference. For example, continuous “white” noise may be far more tolerable than a softer noise that is intermittent. Some people are more sensitive to low, rumbling noises than others.

You usually get what you pay for, though, and there is a gradient of improvements. Some strategies may be fairly cost-effective, but they won’t necessarily get you anywhere close to recording-studio sound isolation. Sadly, some people spend a lot of money trying to reduce noise and end up not being much better off because they didn’t understand the best strategy for their situation and unique source of noise and how it’s actually being transmitted through walls, floors and ceilings. This is one of the areas of construction where I’ve learned through experience that this isn’t really a good area for DIYers to address — not because the construction is difficult, but because the solutions are complex and first-timers probably won’t be able to predict the end result with any level of certainty.

The most common objectionable situation is that you can hear people talking in the next room. Your options here are to install an acoustically absorptive material on the common walls, such as Homasote panels, either fabric-covered and exposed to the room, or underneath the Sheetrock. A more effective solution is to add a product called QuietRock — basically, Sheetrock with a special acoustical core — over the existing wall surface. This will help, but probably isn’t going to be perfect.

An additional strategy is to increase the mass of the wall, maybe with another layer or two of Sheetrock. Ideally, you can get inside the cavity of the wall and install acoustical batt insulation. A heavy masonry wall would be optimal, of course, but seldom practical.

Historically, a resilient suspension system for holding the Sheetrock has been used to reduce noise transmission, but it’s been my experience that unless this is installed very carefully by someone who knows what they are doing, this is often not very effective and can be a waste of money.

If the noise is coming from the street, you may be able to install dense landscaping which will cut down the noise level significantly. And while you might try installing acoustically designed windows, unless you also upgrade the walls to a similar noise reduction level, street noise can easily get through.

The key to the success of any wall or ceiling solution is using special acoustical sealant to caulk all joints, and to use special sound covers behind electrical outlets, switches and light fixtures so that noise doesn’t sneak through. Surprisingly, small gaps can defeat a lot of hard work and money. (As one acoustical engineer told me, an ant shouldn’t be able to get through.) And failing to trace the full path of noise through the structure can also mean wasted money. Noise might be traveling under a door, transmitted through the ductwork or through the ceiling joists.

If your source of noise is mechanical equipment, such as a furnace, you may need to look into ways of mounting the equipment so that its vibration is not being transmitted through the structure. Often, you can install special acoustical vibration dampers.

If it’s the person upstairs who is causing you grief, you may be dealing with impact noise rather than airborne noise, which requires a completely different strategy. Even heavy concrete floors are no match for impact noise. (I remember as a college student, one of our favorite pranks in the dorm was to drop metal ball bearings on our concrete floor to torture our poor neighbors on the floor below.) The best way to deal with impact noise is to have a floor that is either highly cushioned — such as carpet on a thick pad — or add a special cushioned layer below hardwood or tile floors, which will then need to “float” above the actual structure.

An acoustical engineer can be an excellent investment to make sure that you aren’t wasting your money, since different types of noise require different strategies, and different strategies have different levels of effectiveness. Especially in a condo situation, where you may need to prove a certain level of sound isolation to your homeowners association, an acoustical engineer can take before-and-after measurements of sound levels to prove your compliance with the condo’s rules.

The science of acoustics is complex and the building code is filled with terms like “sound transmission class” (for airborne noise) and “impact isolation class” (for impact noise) to be able to compare different construction systems. If noise is disrupting your life, I highly encourage a consultation with a professional. And certainly, if you are thinking about remodeling or adding to your house, it is far, far less expensive to incorporate noise-reduction features when it’s being built initially than afterwards. Talk about your noise concerns with your designer.

Richard Morrison, AIA is a residential architect and interior designer with a Bay Area practice specializing in home remodeling. His website is richardmorrison.com.