Is there a difference in the effectiveness of an earthen embankment compared to a noise barrier in general—and a Greenwall in particular? Definitely, but can you name three? We’ll list them for you in this blog post.

Is there a difference in the effectiveness of an earthen embankment compared to a noise barrier in general—and a Greenwall in particular? Definitely, but can you name three? We’ll list them for you in this blog post.

Reducing Noise Pollution

There are several methods for reducing noise pollution. In our previous blog post, we mentioned speed bumps, low-noise asphalt, earthen embankments, and noise barriers. The latter two are the most effective because they physically block and deflect the sound. The sound is thus literally stopped, which results in greater noise reduction than simply reducing the source noise. It stands to reason that a noise barrier is even more effective than an earthen embankment, but how do you explain that?

How an Earthen Embankment Works

An earthen embankment between a source and a receiver causes the sound to be deflected, forcing it to travel a longer distance from the source to the receiver. The sound waves are partly reflected by the mass of the embankment and partly deflected upward. Once at the top of the embankment, the sound wave will again propagate as an unobstructed sine wave.

The advantage of this type of embankment is that it is relatively inexpensive. Many municipalities, contractors, or project developers have soil on hand that can be used to build an earthen embankment. Sometimes this is (Class I) contaminated soil, which is permitted for this application. Sometimes it is also soil that is generated during the construction project and does not need to be hauled away.

The disadvantage of an earthen embankment is the amount of space it takes up. An earthen embankment has a slope of⁴⁵⁰, or a height-to-width ratio of 1:1. In practice, this means that a 3-meter-high embankment takes up 6 meters in width. Furthermore, maintaining the surface of an earthen embankment requires significant effort: for every^{1 m}of embankment that is 3 m high, 8.5^m² of green space must be maintained.

Effect of a noise barrier

A noise barrier is a vertical barrier between the source and the receiver of the sound. The sound is either reflected or absorbed by the barrier. Only sound waves that reach the top of the barrier reach the area behind it.

The advantage of a noise barrier is that it takes up very little space—about 50–100 cm. This means that the usable area of the garden or lot is much larger. A noise barrier also has a higher effective value in acoustic calculations. The effect is therefore significantly better.

A noise barrier is also less expensive to maintain: it has 30% less surface area to maintain than an earthen embankment.