|Sound Reduction & Test Infomation|
You can view examples of both Domestic and Commercial sound barriers in our gallery.
Domestically to screen all types of unwanted noise you can use our 'Traditional or Estate' garden walls these can be built to a height of 3m and use our IWS 75mm sound panel.
For heights over 3m and up to 5.1m our Barrier Wall system can be used. This also uses our 75mm sound panel.
The level of Sound reduction that can be achieved is based upon many factors such as Terrain, Noise Source & Type, Wall Height etc. An exact decibel reduction can only be calculated by an Acoustic Engineer but the Documents and Videos below will help you gain an understanding of what noise reduction maybe achieved.
Human Perception of Sound
The threshold of perception of the human ear is approximately three decibels, and a five-decibel change is considered to be clearly noticeable to the ear. This is primarily due to the logarithmic measuring metric typically associated with decibels. As Figure 3.1 demonstrates, a 10-decibel change would be perceived to be twice as loud.
Perceived Change in Decibel Levels
Distance Attenuation Estimations
When the distance is doubled from a Line source the sound level decreases three decibels.
Example: If a sound level is: 70 decibels at 15 meters it will be 67 decibels at 30 meters, and 64 decibels at 60 meters.
When the distance is doubled from a Point source the sound level decreases six decibels.
Example: If a sound level is:95 decibels at 15 meters it will be 89 decibels at 30 meters, and 83 decibels at 60 meters.
Decibel Levels of Common Noise Sources
Many different properties affect the noise level of a specific source type. For example, three lawn mowers may have three different noise levels because of differences in each specific piece of equipment. Noise level also depends on the distance from the noise source and the attenuation of the surrounding environment.
Figure 1.3 provides a rough estimate of decibel levels of some common noise sources.
Rules of Thumb
WHEN A SOUND INCREASES BY 10 DECIBELS, THE SUBJECTIVE RESPONSE IS A DOUBLING OF LOUDNESS
Example: 60 decibels to 70 decibels = twice as loud
PERCEIVED CHANGE IN LOUDNESS
+ 1 dB - UNNOTICEABLE
+ 3 dB - BARELY PERCEPTIBLE
+ 5 dB - QUITE NOTICEABLE
+10 dB - SOUNDS TWICE AS LOUD
+20 dB - SOUNDS FOUR TIMES AS LOUD
WHEN THE DISTANCE IS DOUBLED FROM A "POINT" SOURCE, THE SOUND LEVEL DECREASES BY SIX DECIBELS
15 meters = 60 decibels
30 meters = 54 decibels
60 meters= 48 decibels
WHEN THE DISTANCE IS DOUBLED FROM A "LINE" SOURCE THE SOUND LEVEL DECREASES BY THREE DECIBELS
15 meters = 70 decibels
30 meters = 67 decibels
60 meters = 64 decibels
A DOUBLING OF ENERGY YIELDS AN INCREASE OF THREE DECIBELS
Example: 85 decibels + 85 decibels = 88 decibels
You can view more examples of both Domestic and Commercial sound barriers in our gallery.