Long used as an inexpensive approach to sound control, the resilient channel can add up to five or more STC points, though that is not usually enough to gain significant noise reduction.  To boost sound control capabilities, mass can be increased or absorbent material added within the wall cavity to cushion the channels and "soak up" the sound waves.  Hat channels, Z-channels and similar systems resemble true resilient channels, but are too stiff to allow movement, and consequently are acoustically ineffective.  After installation, it is advisable to check the wall for flex-no "give" means the channels are too rigid to be acoustically effective. 

Its complicated installation process has earned the resilient channel a poor track record.  Proper installation is critical.  A contractor can "short out" the resilient channels by merely screwing long screws into the wood studs behind the channel-a misstep that will cancel out any advantage of using a resilient channel.  Industry experts note that the vast majority of resilient channels are faulty due to poor installation, and some architects and engineers are reluctant to specify them for that reason.

Sound Boards.   Made of compressed wood, sound boards function as a thick paper cushion or damping layer between studs and drywall, with the assembly addressing sound control on two fronts.  The drywall provides the mass to inhibit sound transmission, while the lighter-weight sound board traps noise in higher frequencies passing between rooms or exterior walls.  The extra labor and material cost required to achieve relatively minor increases in STC, constitute the main drawback in sound boards as an effective sound solution.

Many of these traditional methods have substantial drawbacks, notably their tendency to increase labor and material costs.  Further, in some cases, the depth of the required partition takes up valuable floor space.  Installation is critical and often complicated.  Even seemingly minor installation mistakes will have a direct bearing on the effectiveness of the technique.  

 

Why Sound Control Matters

For years, interior walls were made of large studs covered with wood lath and several layers of plaster-a far cry from the thin walls that are prevalent today.  Consequently, noise is on everyone's agenda, from consumers to regulators to litigators. 

 

 

Consumer Demand

The discerning tastes of consumers have worked to create the trophy building.  "Developers are asking for so much more out of every square foot," says builder Adam Elias of Idaho-based Elias Construction. "We're building much, much nicer houses than we did ten years ago, and buyers of these houses are more sophisticated than they've ever been."  Today's apartment and condo dwellers are paying top dollar for their units-and with high expenditures come high expectations, particularly when it relates to having a quiet space. Adding to the demand for silence is the fact that more Americans are working at home-a scenario that makes acoustical isolation and the immunity of a dwelling unit to city and neighbor noise even more of a priority.    

 

Today's consumers demand a quiet living space. Photo courtesy Supress Products