Airborne and Impact Noise – What’s the Difference?
Are you a homeowner interested in making your home noise-free? If that is the case, chances are that you will benefit from learning more about airborne and impact noise. Namely, while you may find all noise equally frustrating, different types of noise are handled in different ways.
Most noise is airborne, meaning that it is relayed through the atmosphere. This type covers everything from the conversations of passersby to noisy cats on February nights.
Impact noise, on the other hand, is created through the physical impact on building mass. This can include sources such as footsteps or slammed doors.
Even though a house is physically isolated from all sides, noise can still find its way inside. These are some basic principles of noise transfer.
Sound can loosely be defined as a vibration that affects and travels through a certain medium. In most cases, this medium is the atmosphere. Hence, when these airborne vibrations hit a wall or window, they make their whole structure vibrate. This, in turn, makes the indoors atmosphere vibrate with somewhat less intensity.
What causes airborne noise problems is when elements of the home do not meet the proper standards. For example, even a soundproof door may fail to suppress noise if there are gaps between it and the frame. What’s worse, it doesn’t take a large opening for a great increase in noise to take place.
Impact sound, however, isn’t transferred through the air at all. Instead, once a part of the building’s physical mass suffers an impact, the resulting vibration radiates onto adjacent surfaces. In simple terms, this type of sound will reach you by traveling through the structure of your home. That’s why it is also known as structure borne noise.
Although they might appear as two separate events, the difference between these types of noise is mainly formal. In reality, they cause each other. The airborne sound makes the building mass vibrate, while structure noise makes the airborne sound which reaches your ears.
How to Prevent Airborne Noise
As we already mentioned, airborne noise can come from a variety of sources. These may include:
- Construction work
- Strangers’ conversations
- Stray cats or dogs
- Electronic devices
There are several COMMON APPROACHES TO PREVENTING AIRBORNE NOISE:
- Using noise-absorbent surfaces. This approach requires the use of specific materials which decrease the sonic energy of the noise upon contact. The energy absorbed this way transforms into small amounts of thermal energy.
You normally employ these surfaces architecturally, when planning walls, floors, and ceilings. Other than the type and density, the breadth of the used surface also plays a significant role in absorbing noise. Also, if you cannot change the dimensions of a surface, you can strategically place an opening behind a wall. This way, you can get air to perform a function similar to what these materials do.
Overall, using noise-absorbent surfaces like these foam panels cannot entirely replace using noise-proof surfaces, but it can add to their effect.
- Using noise-proof surfaces. This way, you decrease the amount of noise entering a building from the outdoors space by blocking it with mass. To prevent noise transmission this way, you need materials of proper density and a controlled number of openings.
Many employ this method in living areas. For instance, all the walls in your home have certain noise-isolating qualities. The exact degree of isolation you can manage depends on the shape, structure, and materials of a surface. A common way of combining both techniques is putting a layer of absorbent material over the wall.
- Finally, you can reduce airborne noise by simply reducing the number of openings wherever possible. Well-made and fitting doors and windows are the simplest way to make a drastic difference in the amount of noise.
Controling Structure Borne (Impact) Noise
If you live in an apartment building, chances are that you are familiar with a wide range of neighborly sounds. These sounds may vary from footsteps from the apartment above yours to items dropping on the floor in adjacent apartments.
In these cases, the sound clearly does not travel through the air. Instead, the impact on the floor surface creates a vibration which travels across the building mass. Ultimately, it transmits to your surrounding atmosphere, thus reaching you.
Naturally, such impact noise is mainly an architectural concern. When designing a building, the planners must take impact noise transmission into consideration. Still, impact-borne noise is also highly dependent on less predictable factors, such as the location of the impact.
Absorbent materials stuffed inside walls for reducing airborne noise can be equally helpful when it comes to impact noise.
There are, however, ways to specifically reduce impact noise:
1. Floor elements
The first and simplest way to reduce general impact noise levels is to use carpets and similar floor elements. Some are specifically designed to reduce impact noise levels.
2. Managing gaps
Secondly, it is important to make sure there are no gaps in the structure, as the sound can resonate there. Likewise, any presence of pipes in a wall can increase impact-borne noise levels.
3. Acoustic underlays
Acoustic underlays are layers of soundproof materials which you can place under the floor surface. This way, you don’t depend on altering the construction of the building. Instead, you have a simpler and faster solution at hand.
4. Isolation Hangers
If, however, you would like to reduce noise coming from above, you can resort to ceiling isolation hangers. These elements, located on the ceiling, have the right shape to break the path of noise vibrations. Similar to those are sound isolation clips, which twist acoustics to your benefit. What’s more, they often employ materials such as rubber, which both deflects and absorbs noise.
More on Aiborne vs. Impact Noise
The best time to think about noise control is likely during construction. However, you are in no way without options. Today, it is possible to invest in a number of soundproof solutions. These vary from special doors and curtains to devices you can install on walls and ceilings, such as sound clips.
Knowing the difference between airborne and impact noise is important for finding the solution which works for you. All things considered, understanding what exactly causes your problem is the first step to properly upgrading your living area.