Walls are the only separation between you and your neighbors when you live in a  densely-populated area, and privacy sometimes goes out the window. People hear  their next-door neighbors talking, footsteps from above or even music blaring  through the walls. Sound transmission between units is one of the biggest  complaints among condo dwellers. Noise can also come from ceilings, doors and  windows, so living in a condo can take some getting used to.  

 “One of the major problems is people upstairs, which is footsteps. That is a  major issue because these condos nowadays, there’s really nothing there to block any sounds,” says Joseph Drago, owner of New England Soundproofing located in Waltham,  Massachusetts. “Even a few years ago, what they used to do is just put in some extra insulation.  The problem with that is insulation only muffles airborne sound, but footsteps,  subwoofers, it doesn’t get rid of the vibrations.”  

 Many newer buildings use concrete structures to incorporate more floors and  units. Concrete may be more durable, but sound-wise, it can pose a challenge. “One of the biggest misconceptions is that if you have a condominium with a  concrete slab then there won’t be any issues of sound transfer, and that’s completely untrue, it’s just a different type of sound,” says Steve Haas, president of SH Acoustics in Milford, Connecticut. “In a frame construction when you’re dealing with something not as stiff, the sound you’re going to hear is really a thud, the low frequency sound, especially heavy  walkers can really be heard below. Whereas in a concrete, there is much less of  that thud, and it’s more clickety-clack from heels and vibrations that’s just going to resonate through concrete.”  

 While some noise in shared living spaces is normal, if you can clearly hear your  neighbors’ conversations or TV through your walls or ceiling, you have a noise problem. If you’re willing to make the financial investment, there are innovative noise  reduction solutions that can turn an older condo unit into a sanctuary of peace  and quiet.  

 “Condos are a major issue. Eighty percent of my phone calls are for condos. A lot  of times now they have that open effect, open dining room, living room,  kitchen. And what happens is the sound will travel; it just goes crazy echoing  in that room and it puts more pressure on the floor, the ceiling and the walls,  and people next door or downstairs can hear it,” says Drago.  

 Sound 101

 The frequency of sound is expressed in wavelengths per second or cycles per  second (CPS), which is more commonly referred to as hertz (Hz). Low frequency  noise is considered 250 Hz and below, while high frequency noise is 2000 Hz and  above. Mid-frequency noise falls between 250 and 2000 Hz.  

 The amplitude or loudness of sound is expressed in decibels. This is a  logarithmic compressed scale dealing in powers of 10 where small increments in  dB correspond to large changes in acoustic energy.  

 When a sound wave hits one side of a wall, it transforms into a vibration, which  will travel from the sheet rock, to the stud and into the sheet rock on the  other side of the wall. Because it does not have any other hard surfaces to  travel through, it becomes an airborne sound again.  

 “You can measure it with a sound meter. The way they come up with the IIC rating  is with a hammer test. They go upstairs and hammer the floor, and look at the  decibels down below,” says Bob Orther, service adviser at Soundproofing America, a national company  that services the New England area.  

 But, many contractors and developers are not well educated when it comes to  soundproofing standards and installation. Federal housing developments follow  fairly strict guidelines for soundproofing that include expensive sound testing  for the units. But, private condo developers rarely adhere to the same  standards. “Even with the new condos, the developers are not familiar or educated on how  sound travels, and they don’t hire a sound professional to say ‘what can I do to the framing to minimize these issues?’ It's a lot cheaper to do it during the construction than after. You should have  about an STC of 50, but it’s really not controlled by the building permits. You have to make sure the  installation is done properly,” says Drago.  

 There's no one industry-wide accepted method of soundproofing, and that’s at least in part because none of them completely get rid of every sound from  above or next door. But, other than retrofitting your entire ceiling with new  insulation and drywall, certain materials can also help dampen sound. “There’s a vinyl material that’s really great at blocking airborne sound, but impact noise is a hard animal to  combat. A concrete structure, you’re not going to have a problem with airborne noises like you would with a wood  structure. Wood in general is not really a good sound-proofer, but if it’s dense enough it can be,” says Orther.  

 Wall to Wall Action

 Common wall dwellings have to meet certain codes that are set in place by either  the local building code or the national building council. A unit of measure  called Sound Transmission Class (STC) will tell you how soundproof a wall or  ceiling is. In most urban areas, a unit must have an STC of around 50 to be  within code.  

 According to industry experts, an STC of 40 is the onset of privacy. Once it  hits 50, very loud sounds such as musical instruments can barely be heard. At  60, most sounds are inaudible.  

 For soundproofing a residence, it’s important to minimize vibration from one surface to another and some believe  the best way to do that is by adding shock absorbers between the ceiling or  wall in an existing structure.  

 “You can float a ceiling, completely isolate your ceiling with clips, screw those  up to some kind of wood structure, or directly into the concrete with masonry  screws,” says Orther. “Once you put the drywall in there, there will be a quarter inch gap around the  perimeter that doesn’t touch the adjoining walls. It actually isolates the ceiling from the structure  above. It’s expensive because you really have to take out your drywall to do it.”  

 One option is to install acoustical insulation, although that means taking walls  down to the studs. Another alternative is using dB-Bloc, a vinyl sound barrier  material, which can be layered behind drywall or other finished wall or ceiling  surfaces to help block noise transmission through common walls.  

 Diffusers and reflectors are used to reshape reflective energy where walls and  ceilings create acoustical mirrors. Diffusers and reflectors keep volume the  same as untreated walls and ceilings while changing the shape of the noise.  

 One way to reduce noise to people below you is by carpeting the floor. The  problem is many people like hardwood floors or decorative ceramic tile, so in  these cases you will need to install a sound-absorbing acoustical mat before  laying down the floor.  

 “Whoever is living upstairs decides, ‘I don't like my carpet anymore,’ installs wood floors, and doesn’t put a soundproofing agent underneath it. And they’re usually doing it illegally because most condo associations require an STC.  But, the main thing they're concerned with is IIC, what’s called an impact insulation coefficient,” says Orther.  

 It’s not just the walls and ceilings you have to worry about when it comes to  noise. Noise can sneak in through any gaps in openings, including doors,  windows, outlets, switch boxes, HVAC openings, and anywhere building materials  meet. “I always tell people, do not put recessed lights in your ceiling, because that's  just a big hole in your ceiling. That said, if you have a concrete ceiling, it  might not be a problem because you’re talking about the impact noise. It will come through the lights,” says Orther.  

 Sealers are very cost effective yet they are often the most overlooked step in  noise control solutions. These can include door seals, automatic door bottoms,  thresholds, and acoustical caulk. Also good for soundproofing are noise  barriers, which are always high density, massive, heavy materials and are  essential for eliminating noise transmission.  

 Of all the things to get upset about when living close to others, sound issues  seem to be among the most incendiary. Lawsuits related to noise complaints are  not uncommon, and some associations are taking matters seriously. “If there is a provision in the bylaws, and they don’t meet that, then there's a serious problem. But there’s things they can put under the floor. For some reason, recycled tires work  great for stopping impact noises going down,” says Orther.  

 Final Thoughts

 While some of today’s condo developers are taking more proactive steps to incorporate noise control  features during the construction process, even newer buildings with concrete  ceilings face many older developments where noise between units is a big issue.  “A lot of the problem is contractors do not have a clue about soundproofing. If  they did, they would save a lot of money on lawsuits. Because if a condo just  gets put up, and residents immediately have issues, they go to the contractors,” says Orther.  

 Unit owners to some degree have to accept at some point that they will  ultimately not have an entirely soundproof home, and some noise will likely  leak through. “Depending on how loud the noise is, you can still hear something. I press that  because once people get in their head of this noise, it drives them crazy. Now,  I have to convince them almost like a psychiatrist to say “it’s a noise reduction and I'm happy with it.”  

 “I think that's very tricky,” says Drago.   

 Keith Loria is a freelance writer and a frequent contributor to The Chicagoland  Cooperator. Editorial Assistant Tom Lisi contributed to this article.