Airborne Noise vs. Structure-Borne Noise: What are the differences?

When being in your apartment, you are likely to hear a lot of sounds, including noises. All these sounds enter your house through several mediums. For instance, the gossiping sound you hear might come from the adjacent room. Besides noises from neighbors, traffic noises are a constant nuisance. They too enter your room through the air. You might also hear doorsteps of people walking upstairs. All these are different types of noises that are transmitted into the room via different mediums.

Now, there are two major mediums through which sound waves and noises mostly pass, those are solid surfaces and air . Noise transmitted via air is called airborne noise while the noise that is transmitted through solid objects and surfaces is called structure-borne or impact noise. In this guide, we would look into the detailed differences between airborne and structure-borne noise.

What is Structure-Borne Noise?

Structure Borne Noise

The noise that’s produced when an object hits another object is called structure noise or impact noise.

When two solid objects strike against one another, the sound generated as a result travels through solid surfaces. Such noise is called impact noise . The best example of impact noise or structure-borne noise would be footsteps. Remember that footsteps you hear coming from upstairs? It’s because the effect of the footstep on the floor results in soundwaves that travel through the floor passes through your ceiling and enters your room.

Therefore in simple words, structure-borne sound or impact sound implies the physical impact of noise on solid surfaces and materials. Impact noise occurs because the effect of the action causes both sides of a solid surface to vibrate, generating sound waves.

It’s difficult to soundproof against impact noise because it travels faster, especially through denser surfaces. Impact noise, unlike airborne noise, doesn’t propagate through air. They need a solid surface for transmission. Therefore, the only way to impede their transmission is to create a hollow space between opposite sides of a surface, so that the soundwaves are trapped until they become weak.

What is Airborne Noise?

What is Airborne Noise

Airborne noise is the noise that’s transmitted through the air. It’s the sound of actions like talking, TV noise, barking, laughing, etc. Actions like these generate sound waves that propagate through the air and hit a solid element, causing it to vibrate. These vibrations then pass through the solid structure, reaching you at a faint volume.

If your neighbor is a party freak you are likely to experience airborne noises at night. When your neighbor plays songs at high volume, the sound from the system radiates in all directions and travels through the air. These sound waves then hit every solid surface, in this case, the common wall. Don’t you feel like the windows and doors of your room are vibrating? It’s because the sound waves are hitting these solid surfaces and traveling through them.

Each one of us is sure to have experienced airborne and impact noises at some point. Now that you have understood what is airborne and impact noise, let’s go through their differences in detail below.

What is The Difference Between Airborne Noise and Structure-Borne Noise?

Difference Between Airborne Noise and Structure-Borne Noise

In simple terms, airborne noise is transmitted through the air and then through solid surfaces whereas structure-borne or impact noise needs a solid surface for its transmission. Also, the latter travels faster than the former, because it uses solid objects as its medium of transmission. It’s obvious that airborne and impact noises are produced under different circumstances. Let’s find out how they are generated.

What Causes Airborne Noise?

Whatever energy causes the air to compress, airborne noise is generated. When the surrounding region of air is compressed, it immediately attains a higher pressure. Consequently, low-pressure regions are formed surrounding the high-pressure area . This process of compression – rarefaction allows the soundwaves to move away from the source of its production at the speed of sound. But since, air particles are loosely held and not as dense as solid ones, airborne noise travels at a slow rate.

The noise produced from the honking of vehicles is entirely airborne in nature. Or perhaps, you can hear faint music coming from a  faraway place, it’s an example of airborne sound.

Needless to say, airborne sound or noise enters the room through windows and doors and not through ceilings and floors. Airborne sound waves are likely to hit the walls too.  Therefore, if you are tired of hearing loud music at night, consider soundproofing your doors and windows, and adjacent walls.  Consider the soundproofing options given below to soundproof your room against airborne noises.

How can Airborne Sound be Reduced?

One of the effective ways of reducing airborne sound is by implementing acoustic absorption techniques. Acoustic techniques significantly reduce the intensity and amount of sound that’s reflected back into the room. We have enlisted below how you can soundproof a room by implementing acoustic solutions.

  • Install Acoustic Wall Panels

Acoustic wall panels are easy to be installed and slim. They come with improved absorption qualities, which reduce the effect of sound considerably.

  • Install Acoustic Slabs

Apart from acoustic panels for the walls, there are acoustic slabs too, that absorb airborne sounds and traps them inside the cavity partition formed by metal party walls and timber. This reduces reverberation significantly.

Besides doing acoustic treatments to walls, there are other basic steps you can take to reduce the effect of airborne noise. For instance,

  • Seal Existing Gaps and Holes Using Acoustic Sealant

Sound can enter through any negligible crack, hole, and gap. Therefore, make sure the doors and windows are in proper condition. Fill any hole, gap, or crack with an acoustic sealant caulk. It’s an airtight sealant and is great for deadening sound waves.

Apart from the ones mentioned above, one can utilize sound insulation techniques too. They are equally effective like acoustic solutions. The only difference is that soundproofing techniques don’t absorb the sound waves. They rather block the sound waves from passing through ceilings, floors, walls, doors, and windows.

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What Causes Structure-Borne Noise?

We have already mentioned how structure-borne noise is produced from an effect on a solid surface. There’s another way in which impact noise can also be generated. When a low-intensity sound hits a solid surface, the noise generated as a result is also called structure-borne sound.In either of the case, the soundwaves or noise will travel through a solid surface and then radiate in all directions once it reaches the other side of the solid surface.

Have you ever felt a vibration when you stand at the platform and a train rushes by your side? The vibration is nothing but impact noise. The interaction between the wheel and rail causes a powerful vibration that’s being radiated around it.

Sometimes, you might have also noticed your walls, beds, or windows vibrating, when your neighbor plays loud music. That’s also an instance of impact noise. The sound waves hit the walls, causing them to vibrate.

Now that you know how impact noise is generated, wouldn’t you try to soundproof your room against impact noises? Let’s see how you can it.

How can Impact Sound be Reduced?

There are multiple ways in which one can reduce impact noises. Let’s go through the several solutions one by one:

  • Install Carpet Padding

When it comes to reducing the impact of the sound while it tries to reach you, the first affordable solution is to install thick carpet padding. Carpets are thick and dense,  and are, therefore, effective absorbers of sound waves. They come with sufficient damping and absorption elements that reduce the impact noise largely.

  • Use Resilient Underlayments

Install resilient underlayment beneath your main flooring. To get even better soundproofing results, add carpeting on top. By doing so you will improve the thickness, meaning that soundwaves have to travel more. Therefore, they are likely to weaken in the process.

While doing an underlayment consider materials like foam, fiberglass, and rubber. They are the top-rated sound-absorbing materials available in today’s market. They significantly reduce the intensity of the impact.

  • Use Soundproofing Compound

Soundproofing compounds are equally effective in blocking impact noise. If you have installed soundproofing techniques for airborne noise reduction, you can do the same for reducing impact noise too. They are excellent sound dampening solutions. By dampening the intensity of the sound, they reduce the effect of the structure-borne noise. 

Using soundproofing compounds are used in subflooring works. Wondering how a soundproofing compound works? Well, it works by dissipating the sound waves, that travel through it. In the process, it reduces the intensity of the sound waves too.

  • Creating Soundproofing Floors and Ceilings

Remember that impact noise can come from any solid surface. Therefore, to get absolute soundproofing effects, you must soundproof the ceiling, floor, and wall of your apartment. By soundproofing all surfaces, neithernoise will enter your house nor will it leave your house.

  • Creating resilient channels and adding drywall can even enhance the sound insulation results.

Irrespective of the type of sound you are tired of hearing, you obviously would like to get rid of it and enjoy peaceful living conditions. We have listed convenient and affordable solutions that are sure to give you evident soundproofing results.

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The Bottom Line

The ideal time to install the necessary soundproofing elements is during construction. But, if your apartment doesn’t have any soundproofing element installed, and you are left with no choice, it’s worth getting a renovation done. Investing in the right soundproofing solutions is never a bad decision.

But, before you decide what techniques to install, it’s important to identify and differentiate between airborne and structure-borne noise. Understanding what type of noise is causing the problem is the core to upgrading your house the right way.