Types of Noise Barriers

Noise barriers are objects that are lined along roadways and other areas where noise is a problem to help stop the sound from traveling. Depending on the situation, the noise level and the location, there are a lot of potential materials and types of noise barriers that can be used.

Earth Mounds

• Perhaps one of the most basic types of noise barrier is a hill formed from earth, often called berms. These berms look like hills, because that's essentially what they are, but they can serve an aesthetic as well as a practical purpose. However, while sound doesn't travel through or over the berms as well as it might, these mounds take a lot of space and time to build, and they aren't practical in places where space is at a premium like city streets.

Trees

• A thick line of trees, which is often used as a windbreak in highway construction, also has the ability to block noise. Evergreen trees are used because they keep their "leaves" all year round, and they act as a noise barrier the whole year as well. Like earth mounds, trees can be used to add an extra bit of natural beauty that has a practical purpose. However, the trees have to be quite thick, which means they take up a lot of space.

Walls

• Walls, typically made out of concrete and layered with materials that help diffuse sound, are often a solution that's used in residential and city areas to help block out sound. These walls can only be built to a maximum of about 25 feet or so in height, but they aren't thick, and they can be put on raised highways and built along narrow roads to help block sound where other forms of noise barrier wouldn't be as effective.

Density

• While a noise barrier can be made out of almost anything that doesn't let sound pass right through it, the measurement of 20 kilograms per square meter is the official measurement of density that acts as a baseline. Any material with that amount of density works as an efficient noise break, regardless as to whether it's made from wood, metal or concrete.