Keeping The Noise Down
A sound occurs when an ear senses pressure variations or vibrations in the air. Noise is unwanted sound. The brain relates a subjective element to a sound, and an individual reaction is formed.
Numerous studies have indicated that the most pervasive sources of noise in our environment today are those associated with transportation.
Motorway traffic noise tends to be a dominant noise source in our urban, as well as rural, environment.
What Are Noise Barriers?
Noise barriers are solid obstructions built between the road and residential/office areas along the motorway.
These barriers reduce overall noise levels for the occupant living adjacent to major roadway networks. Effective noise barriers typically reduce noise levels by 5 to 10 decibels (dB).
This can reduce the noise level by as much as 50%, and for example, a barrier which achieves a 10-dB reduction can reduce the sound level generated by a typical tractor unit pass-by to that of a standard car.
Noise barriers can be formed from earth mounds or ‘berms’ along the roadway, however for it to be most effective noise barriers need to be tall, this is difficult to achieve using such a construction, hence the use of walls/structures that can extend up to 8m in height.
These structures can be made from various materials the most common being;
- Mixed Materials
To effectively reduce sound transmission through the barrier, the material chosen must be rigid and sufficiently dense (at least 20kg/m2). All noise barrier materials are equally effective, acoustically, if they have this density.