Noise is an especially delicate issue within condominium associations, where complaints can create disputes that pit association members against each other while embroiling the board in bitter, highly personal disagreements.

Noise is a subjective issue and as a result, noise disputes can be extremely difficult to resolve, sometimes resulting in costly litigation.

Another thing that makes noise control so complex is that while noise is measured in dBs, the frequency of the noise can contribute greatly to the noise complaint, and the frequency probably will not be reflected in the dB number.

Noise is a subjective issue, and can be difficult to resolve. When the sound of noise of your own, it is merely sound, but when it is generated by a neighbor, or from outside, then it becomes annoying noise.

Noise is an especially delicate issue with condos and cooperatives. When cooperative and condominium boards ignore these complaints, residents may have no choice but to go to court. If this happens, the suit may become public, costly, and affect the resident’s ability to sell the unit.

Historically, in residential and especially in multi-family dwellings, plumbing noise has been a major distraction, while in single family homes, dishwashers, showers and laundry can be scheduled not to interfere with quiet dinners and sleep, multi-unit residents have no such luxury… they must live with the water use whims of their neighbors.

But times are changing. The growing popularity of high priced multi-unit housing for the aging baby boomer generation is starting to focus a great deal of consumer attention on sound isolation. Knowing how to quiet HVAC, plumbing, and impact noise is a powerful tool in the market. Consumers are demanding a quieter environment.

With baby boomers moving from single family homes into retirement condominiums, builders need all the noise reduction they can get.

Noise is unwanted, unpredictable and uncontrollable sound. But sound does not need to be loud to be labeled as noise.

When working on open plan office spaces, the hardest sounds to eliminate are those of the HVAC system. HVAC vibrates at a continuous low frequency hum - between 50 and 70hz. This is approximately the range of human hearing where sound becomes omni-directional - we cannot exactly locate the source of a sound. This is also the range of human hearing where we can even feel a small amount of vibration, which, after prolonged exposure, could cause nausea.

A Cornell University Study has found that noise is harmful to mental health as well as physical health.

The Cornell University Study also showed that workers in open plan offices where there are constant low levels of low frequency noise are less likely to be creative. Workers in noisy offices are 40% less likely to continue to work on a complex task than workers in quiet workspaces.

The human body reacts to these types of noise irritations though a complex set of physiological stress responses, resulting in a rise in blood pressure, a change in the heart rhythm, and an increase in hormone levels. If noise is sustained, over time the stress can lead to cardiovascular or circulatory problems. Noise can interfere with sleep, leading to attention and concentration lapses the next day.

Shared walls mean noise. Shared corridors mean less privacy. According to an exit survey, women who live alone perceive unidentified noise from outside their apartment as a threat to their safety. According to the U.S. Census Bureau, more than 25% of all households have a single occupant, mostly women. Over 1/3 of all households are run by single parents, again, mostly women. Security, or the perception of security, is becoming a bigger and bigger issue.

Senior renters should not be overlooked by multi-family professionals. While they are less likely to be renters than those in younger age groups, they have a much lower turnover rate. Security is a major issue for senior citizens.

U.S. Business Travelers list noise from neighbors as the #1 sleep inhibitor.

What good are luxury bed linens, upgraded mattresses and fluffy towels in a hotel room, when you can hear the neighbor flush the toilet at 2 a.m., people walking and talking in the hallways at all hours of the night, or the television booming from the room next door? There are hotel chains who are trying to distinguish themselves from one another by offering ‘a good night’s sleep’. Some have even gone so far as to designate ‘quiet zones, or quiet floors’ in their hotels to further assure the guests peace and quiet.

If developers would simply consider noise control in their original design, the hotel owners wouldn’t have to try to find ways to mask the noise.

More than half of business travelers report that they don’t get enough sleep on the road, according to the 2003 National Business Travel Monitor Survey. Also, women who travel alone perceive unidentified noise as a threat to their safety. It would behoove hotel developers to keep that in mind if they want to retain their female business traveler.  

Much of what is learned in school happens through hearing and listening. If the noise levels are not designed properly for classrooms, students can be prohibited from optimal learning. Careful consideration must be given to reverberation times, particularly in the primary grades where the young student’s ears are not fully developed. They also do not possess yet, the ability to ‘interpret’ what is being said if they don’t hear all the words. They are unable at this stage in life to ‘fill in the gaps’. Children with normal hearing can miss as much as a third of what teachers say. This is why good acoustical design of the classrooms is imperative. Those who continually miss key words, phrases, and concepts because of poor listening conditions are significantly disadvantaged.

To solve airborne noise, you have to have mass. The more mass the mass the better the STC. To solve structure noise, it’s the complete opposite. It is not so much the function of mass as it is the function of isolation and vibration breaks.

Architects may specify STC/IIC ratings of walls and floor – ceiling assemblies, but if the specification and design measures are not included to prevent flanking (pathway that can let noise snake around the wall or floor or even under the floor ceiling assembly) then the effectiveness of the specification is greatly reduced.

For example, a 1/16” crack at the floor line can reduce a 50 STC wall design to a 39, which is well below code.

An electrical outlet in a wall, if not properly insulated, can also greatly reduce the STC value of a wall.   

What do many homeowners want to hear after a long day at work? Perhaps it’s nothing. Only about 30% of homebuilders offer sound attenuating interior walls as standard pre-priced option for their homebuyers. The ones that do offer this option find many of their homeowners want it and are willing to pay for it.

Having a quiet and peaceful back yard is also desirable. Considering quieter air conditioning units can help keep annoying noise down in the backyard.

Some residents have problems with noise from a street that backs up to their property. Many homeowners invest in landscaping to keep down unwanted street and highway noise. Unfortunately, adding trees and shrubs won’t help to abate the noise very much. Using a professional acoustical consultant is necessary to avoid wasting money on products and plants that won’t help the situation.

AcoustiControl is an acoustical engineering firm that delivers exceptional technical expertise in plain, easy to understand language.

Speaking of language, don’t feel bad if you have spelled acoustical as ‘accoustical’... many people do!