A kennel full of barking dogs has a sound level of 80 decibels (dB). A 50dB sound level at the lot line is acceptable in most cities and to most residential neighborhoods. By subtracting to 50dB desired maximum sound level from the 80dB sound of barking dogs, one can see that a wall or roof assembly must be capable of reducing sound by at least 30dB to achieve the desired maximum level of sound.

Construction assemblies are rated by their Sound Transmission Coefficient (STC) characteristics. STC ratings are established by certified testing labs for basic materials and for various combinations of materials that make up particular walls, ceilings or roof assemblies. For example, a wall partition of 2x4s with a gypsum board (dry wall) on each side has an STC rating of 34. A partition wall of concrete block with gypsum board attached to resilient channel furring has an STC rating of 52. An insulated glass window has an STC rating of 39.

It is the responsibility of the architect to help choose the materials for walls and roofs that will control the transmission of sound from one space to another. Sound will travel through openings in walls and ceilings.

Care must be taken to seal these openings. Doors must have weather stripping or gaskets at the closures. The intersections of wall and ceiling assemblies must be caulked or sealed. Electrical box wall penetrations must be caulked. HVAC ducts must have sound traps when penetrating sound control walls.

Most kennel spaces and many hospital waiting rooms have walls and floors with hard, smooth surfaces that reflect the sound around the room, causing reverberation.

The ceiling is usually the only surface that can be treated with materials that absorb, and thus reduce, sound. Even though suspended acoustic tiles are made of sound-absorbent material, they do not have enough mass to significantly reduce sound.

One solution frequently employed is to apply acoustic fiber to the structure above. Panels of sound-absorbent materials can also be installed.

Textile surfaces in public areas such as commercial grade carpeting, upholstered furniture, wall hangings and fabric baffles extending from the ceiling contribute to sound control. They also provide an opportunity for hospital and kennel owners to express themselves and create an attractive setting for their clients. And some synthetic carpeting can be almost as easy to clean as tile.

A determination must be made by the Owner, with the assistance of the architect, about the cost of installing a particular product relative to its effect in reducing sound to the desired level.

Not so pretty, but pretty important...

Sound can travel through ductowrk and holes in walls, such as those seen above.