Noise is a key quality-of-life problem for almost anyone living in a  densely-packed urban environment. It's the bane of many a condo-dweller’s existence, and over the years engineers, architects, and designers have tried  any number of ways to reduce the problem of noise in multifamily buildings—some more successfully than others.  

 When Noise Annoys

 As long as people have ears and the ability to use them and live in close  quarters with others, there will be problems with noise. It’s just human nature.  

 Jeremy Feigen, owner of Accurate Construction in Mundelein has heard all the  complaints. “I'd want to say the biggest issue that we're seeing in the years we've been  doing this, and focusing mostly in Chicago, is construction issues. By the time  [our clients] contact us it's: 'I hate my neighbors. I know when they wake up.  I know when their kids go to bed. I know everything that they do. I hear every  time their cell phone rings. I know when they're walking in to the bathroom in  the middle of the night because there's that one squeak right in front of the  floor',” he says. He even had one client who swore she could hear her downstairs  neighbor's cell phone vibrate through her floor.  

 While a great majority of sound irritations come from the inside (kids running  upstairs, loud music or TV), some residents may find that the noise originates  from outside. Michael Ibarra, owner at Soundproof Chicago in Crestwood says  that many of his clients cite noise caused by busy roadways, trains, flight  paths, bars or nightclubs, factories and sirens. But whether inside or outside,  having to constantly deal with sound issues can a lot of unnecessary stress and  disrupt the home environment.  

 Mandy Kachur, a principal consultant with Soundscape Engineering in Ann Arbor,  Michigan, and the vice president of public relations for the Institute of Noise  Control Engineering/USA says, “Sounds that are transient, that come and go, that start and stop”—like hammering a nail into a wall—“or tonal noises, like whistles, tend to be more annoying than a steady broadband  of white noise”—like the hum of a washer and dryer.  

 What distinguishes sound from noise, however, is the ear of the beholder. “Complaints arise from the noise that someone else is making,” says Kachur. “It doesn’t matter how much noise you make.”  

 Noise is Subjective

 Unfortunately, because the concept of noise is so subjective, it is has been  difficult to establish some type of regulations and building codes for it. The  Chicago Department of Environment's Article XXI on Environmental Noise and  Vibration control states that “between 8:00 P.M. and 8:00 A.M., no person shall generate any noise on any  private open space that is louder than average conversational level at a  distance of 100 feet or more, measured from the property line of the property  from which the noise is being generated.”  

 But, herein lies the rub: what the “average conversational level” is differs for everyone.  

 “I could be somebody that talks very loud and thinks that the way I talk is fine.  My neighbors could have a completely different feel on that. So, there really  isn't a set of specific standards that I have been able to find at all with  really any municipality saying that you need to meet a certain decibel level,” says Feigen. “There are areas and cut guidelines for fire control, for example, of exactly  what needs to be obtained with that. That's very specific. But when you get  into the sound control, it's not as specific. It's normal listening levels,  which as you know varies from person to person.”  

 Ibarra adds, “Some people are more sensitive to certain noises than others. If several people  in a building are complaining about the same noise, whether it be environmental  or structural, there is an obvious noise problem. A soundproofing expert may be  called on to evaluate certain factors such as the intensity of the noise, the  construction of the building, and determine if any upgrades need to be done to  address the noise problem.”  

 Sound, By the Numbers

 There are three grades, per HUD, given buildings as it pertains to noise. Grade 1 is luxury; grade 3 is the aural equivalent of living in a cardboard box  on Lake Shore Drive; grade 2 is everything else.  

 STC, or sound transmission class, pertains to what’s called airborne sound—voices, music, dog barks, your neighbor’s kid practicing her violin, and so forth.  

 The American Society for Testing and Materials (ASTM) has developed a ratings  system that assigns an STC number to building materials corresponding to how  effectively it diminishes the transfer of noise. This number derives from a mathematical formula involving sound attenuation  values and transmission loss curves and other technical data. A low number indicates sound flowing easily through the wall—a rating of 25, for example, means you can hear conversations as if the wall  didn’t even exist. Forty is the baseline number, the minimum rating for what acoustical engineers  call “privacy.” Anything above 60 and, as they say in horror movies, you’ll never hear them scream.  

 “The luxury grade has higher acoustical ratings than average grade,” says David Ingersoll, national sales manager for Acoustical Solutions in  Richmond, Virginia.  

 These ratings are used not only to test the quality of sound from room to room,  but also to determine where a residence may be built in the first place.  Builders, for example, cannot construct a condominium too close to O’Hare Airport, for example, because of HUD restrictions on STC.  

 The other sound measure is IIC, or impact insulation class, which measures “impact” sounds, such as the clack-clack-clack of the stiletto heels worn by your  upstairs neighbor as she walks around her ceramic-floored kitchen at 5 a.m.  

 “The biggest challenge now is IIC numbers,” Ingersoll says. “Years ago, it wasn’t an issue, because people used an awful lot of wall-to-wall carpeting. Now, they want hardwood floors, they want ceramic tile,” and those materials don’t naturally dampen noise. “Because there’s no longer a cushion above the floor, it must now be under it.”  

 The solution is to have a layer of one of many materials—recycled rubber or recycled wood are two common choices—beneath the floorboards.  

 Soundproofing

 You know the old saying about walls being “paper-thin?” As it turns out, thin walls do allow the most noise to pass through. The first  rule of quality soundproofing, then, is thicker walls.  

 But as many industry pros will say, to completely soundproof a room would cost  thousands of dollars and it would probably be more economical to move. The  strategies used today can help reduce noise, some more successfully than  others. “Typically, I tell people we can address about 80% of the issue because to tell  somebody realistically you can do more than that, it isn't very feasible,” says Feigen.  

 For those living in condo units, there are several options used to address noise  issues. Ibarra says that windows should be addressed first since they are the  weakest part of a house's walls. He suggests CitiQuiet, a New York company  which makes soundproof windows. Their windows, he says, are “made specifically with laminated glass, and air-tight aluminum frames. This  window is installed as an interior storm window and is effective at blocking up  to 90% of street noise. They are in use in many new construction settings as  well as existing buildings, and even currently installed at the U.S. Supreme  Court.”  

 Another effective product is called Green Glue which is “a liquid damping compound that is applied to standard sheets of drywall,” says Ibarra. “Green glue is effective at blocking airborne noise that travels through walls  and ceilings. It has been gaining popularity in new construction to soundproof  walls and ceilings and has been used for over ten years in retrofit  applications.”  

 Feigen adds, “it's like getting a rubber barrier in between the two layers of drywall. So,  sound that's down below will kind of stop at the middle and bounce back to you  and sounds from outside will help stay out.”  

 A type of cellulose insulation called blown-in insulation can help diminish  noise that is occurring from floor to ceiling. Feigen explains that it is made  of recycled newspaper, making it a green product, and contractors create a  small hole in the wall and use a vacuum to blow it into the ceiling joists.  

 Cork, the old standby used famously by the novelist Marcel Proust in his Paris  apartment, is still effective at blocking sound—mostly impact sound. Because it is renewable, it has its apologists among green builders as an  under-layer in flooring. But cork breaks down fairly quickly.  

 Serious Energy, a Sunnyvale, CA soundproofing and energy management company,  makes a form of damped drywall called QuietRock. A technique called constrained  air damping is used to dull vibrations—in effect blanketing soundwaves. “It’s like a shock absorber,” Kachur explains. These materials are specifically engineered to dull the sound in the frequencies  of human speech, she says.There are two problems with soundproofing. The first is price. “It’s very expensive,” Kachur says. “If you build a five-story condo—that might be prohibitively expensive. But to soundproof the downstairs video room? That’s probably worth it.”  

 The second problem is—it’s an arduous job to soundproof a condo that someone lives in. The place has to be gutted, with new layers added to the floor, ceiling, and  walls.  

 “The hardest part is, once people are in, it’s almost too late,” says Ingersoll. “They need to be built through beforehand.”  

 So if you’re planning on buying a condo or an apartment, you’d better be sure and know how it sounds at Saturday night, or early in the  morning. If it’s too noisy, once you move in, you’ll never hear the end of it.   

 Greg Olear is a freelance writer and a frequent contributor to The Chicagoland  Cooperator.