I came across this Article on HowStuffWorks.com

It had a lot of interesting noise problems and solutions. Check it out!

Turner, Bambi.  “Can you block neighbor noise in a townhome or condo?.”  18 May 2009.  HowStuffWorks.com. http://home.howstuffworks.com/home-improvement/repair/block-neighbor-noise.htm 04 December 2009.

Fundamental Physics:

• Mass transmits vibration energy to spring
• Spring converts vibration energy into heat
• Heat is released into the system
• Mass on post-spring side receives reduced vibration energy

Noise Control System:

Mass: Floor
Spring: Recycled Rubber
Mass: Gypsum Concrete

Mass: Gypsum Concrete
Spring: Entangled Net
Mass: Joist

Mass: Joist
Spring: Resilient Channel
Mass: Gypsum Board

Noise Control System:

• Effects of each component
• Recycled rubber mat works from 1000 Hz & up, reducing high frequency noise
• Entangled net and gypsum concrete work from 400 Hz & up, reducing mid-range noise
• Resilient channels work from 1000 Hz & below, reducing low frequency noise

I visited a jobsite a couple weeks ago. The project had some noise problems. The bedroom on the second floor was noisy. Turns out, the kitchen on the third floor was right over it and the kitchen in the unit behind the bedroom was directly behind the headboard of the owners bed. The poor occupant was listening to footsteps every night and cupboard doors closing all day.

There is a process in noise control that is as important as selecting the right products. That process involves evaluation of expectations, design to the expectations; installation to design and testing for compliance. Any step missed can create a significant problem in the end. In this case, finished units had a ceiling and a wall removed to solve the problem. Costing $25,000 to the developer. The error was made when the project started and would have been an issue no matter who moved into the building.

KEENE believes in following the process to assure quality and we strive to present to architects the proper products and to establish a base point of where the materials will function to match performance with expectations. Better matching and a good system helps as much as any material selection.

Noise Control System: Bottom side ceiling

• The joist assembly provides the foundation of a bottom side noise control system designed according to “MASS-SPRING-MASS” physics.
• A Resilient Channel is the spring and isolation device.
• The gypsum board is the bottom Mass

Noise Control System: Wall/Ceiling interface

• Critical that the ceiling does not contact the wall to avoid flanking path.
• Standard is to “float” the wall up to the ceiling, however, installations are very poor.
• Space Assurance provides a simple method to maintain the acoustical performance of the system.

Sounds of Silence

Check out this Article on BUILDERnews.com

Click below…

In wood construction the typical system includes:

•    Resilient Entangled Net material on top of plywood subfloor in  conjunction with gypsum underlayment.
•    Insulation in the joist cavity.
•    Resilient Channels & gypsum board on the ceiling below – Low Frequency Control.

In concrete construction that same system works well but often the economics are different:

•    Ceilings are often left exposed, limiting the ability to use bottom side resilient materials and insulation.

Flooring Underlayment

•    Recycled rubber mat under hard flooring provides the top of a noise control system designed according to “MASS-SPRING-MASS” physics.
•    The recycled rubber mat is the spring and isolation device.
•    The engineered wood or tile is the top mass.
•    The gypsum concrete is the bottom mass.

Top Side Foundation

•    Gypsum concrete provides the foundation of a top side noise control
system designed according to “MASS-SPRING-MASS” physics.
•    An Entangled Net is the spring and isolation device.
•    The joist assembly is the bottom Mass.

Interesting article on the Commercial Building Products website, October 2009 Issue, SOUND ADVICE FOR ACOUSTICAL DESIGN

Many people believe that the performance standard for multi-family is too low. Frankly, achieving code does not mean achieving quite living. The range of the test excludes some important frequencies well below 100 Hertz. Frequencies as low as 25 Hertz are quite noticeable and some times quite bothersome. Performing to a “50″ does not mean hearing nothing from the neighbors. As the multi-family sits in a lull during this market downturn, it is safe to say that noise is something that should be revisited, especially vibration noise.

A number of excellent acoustical consultants have pushed for a change in the code requirements. Some have asked that the testing metric be divided so that a performance is measured separately in the high and low frequencies. Many have called for an enhancement of the requirement calling for higher performance levels. Cities such as those in Northern California and in Chicago have required STC and IIC standards that exceed the UBC levels. Needless to say, quiet living is still at the top of most owners concerns and will remain there until the last shoe drops and no one hears it!!

In other complaints about our noise standards, there is an industry discussion about how the tapping machine doesn’t reflect the type of noise that an individual makes when walking. This is absolutely true from a reflective noise standpoint. What we create on the topside sounds nothing like me walking, or a woman in high heels. The tapping machine does sound like a herd of horses in the receiving room and the noise from me walking, or the tapping machine is not much different so changing this metric isn’t the most important modification. In other countries there is a recognition that low frequencies are the culprit more than it is in North America.

Changing the standard ASTM tests for E90 and E492 doesn’t seem necessary. Changing the standards that we shoot for does.

STC: Sound Transmission Classification – Measurement of Airborne noise

•    Talking, music, television
•    Single number result over a frequency range from 100 to 3150 Hz
•    50 in a laboratory setting is considered passing by Standard Setting Organizations

IIC: Impact Insulation Classification - Measurement of Vibration Noise

•    Footfall, washing machine
•    Single number result over a frequency range from 100 to 3150 HZ
•    50 in a lab setting is considered passing Standard for Multi-family

Sound: Vibration in an elastic medium

• Originates at a source – Footfall – Speaking

• Travels via an elastic medium – Air – Wood

• Received – Equipment – Human ears

Noise: Response to sound by a receiver

• Loudness – Amplitude

• Pressure – Intensity

• Pitch – Frequency

• Quality – Distribution of Energy