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The 7 Best Sound Absorbing Materials

Sound absorption is a powerful solution to the often unrecognized issue of sound murkiness. Every room we are in – whether the living room at home, the office, sanctuary, or movie theater – has certain acoustics that determine how we perceive sound. From ceiling height, to the types of materials chosen for walls, ceilings, and furniture, almost everything in a room will impact the acoustics. Often these choices, while aesthetically pleasing, can have a negative impact on the acoustics of the space.

This is where sound absorption comes in, a technique that utilizes sound absorbing materials to “clean up” the acoustics so that negative aspects of sound, like echo and reverb, can be eliminated, leaving crisp, clean audio and speech.

In this article, I’ll unfold the concept of sound absorption and list the best sound absorbing materials, including the ones I find to be the most effective for all applications.

Understanding Sound Absorption

Sound absorption is the usual term used, but I like a synonymous phrase that is more explanative: sound control. While it is technically true that sound absorption is absorbing sound, this can easily be misconstrued that all of the sound is being absorbed. In reality, only certain sounds are being absorbed. Thus, we are utilizing sound absorption to control reflections to make an environment more comfortable.

The biggest problems we seek to eliminate with sound absorption are echo and reverb. Although related, they are distinct in how they are heard. Echo is the delayed repetition of a sound as it bounces off of materials and comes back to our ears. The most common example of this is in caves, where echo is pronounced. Reverb is similar, except it has to do with the muddiness created by the reflections of sound all intermingling together. For example, if you made a single sound in a cave, like a shout, you would hear the echo bouncing around and slowly trail off as it loses energy. If you were playing music in a cave, with so many sounds being played one after the other, these would bounce around and intermingle, creating a muddiness to the overall sonic environment.

The solution to echo and reverb is to utilize materials that absorb these unwanted characteristics of sound so all that is left is the desired sound without imperfections created by a room’s acoustics. Sound absorption products range from acoustic panels hung on walls to acoustic baffles and clouds suspended from the ceilings, all dependent on the structure and nature of activity within. The key importance when looking at these products is to ascertain the materials used, as some are better than others when it comes to ideal sound absorption.

The 7 Best Sound Absorbing Materials

There are a number of materials classified as having sound absorbing capabilities. Of those, I find that there are 7 types that can truly absorb sound in a meaningful way, although some are significantly better than others.

1. Fiberglass

Fiberglass Sound Insulation: Benefits and Comparison

AlphaSorb® Fabric Wrapped Acoustic Panel Edge Styles – Square, Beveled, Mitered, Rounded (not available)

Fiberglass is my top choice for sound absorbing material. The material is well-suited to be a excellent sound absorber because of the following three characteristics:

Porous Nature

Fiberglass is made up of fibrous material, meaning it is “soft.” More specifically, it means it is porous, which is perfect for sound absorption as this characteristic allows sound to enter and get trapped within. The energy of the sound waves causes the fibers to vibrate, transmuting some of that energy into heat. This process thus strips the unwanted energy from sound and dampens it.

Density

Although porous, the fibrous nature of fiberglass is dense. This seeming contradiction means that sound can readily enter the material, but it is dense enough to absorb the unwanted aspects of sound we’re trying to strip away to make sound crisp without echo and reverb.

Broad Frequency Absorption

The material characteristics of fiberglass allows for the absorption of a broad frequency spectrum, meaning low to high frequencies sound can be absorbed instead of just parts of the spectrum. This makes fiberglass a more full solution than other sound absorption materials.

When all of this combines, fiberglass stands as the best sound absorbing material, and is the backbone of my favorite acoustic panels, AlphaSorb® Fabric Wrapped Acoustic Panel. These panels are a one-stop sound absorption solution and are an industry-leading product for the top applications requiring outstanding sound control.

2. Mineral Wool

Mineral wool is also excellent at sound absorption and is an industry-standard like fiberglass. The benefits of mineral wool mirror that of fiberglass, as the characteristics of the materials are nearly identical. Mineral wool is a bit more effective at absorbing low end frequencies as it is slightly more dense than fiberglass. That said, when you compare the two, there exists an important nuance that makes fiberglass my preferred choice.

This difference between mineral wool and fiberglass is that fiberglass is semi rigid whereas mineral wool is loose. This means that fiberglass can hold a shape, whereas mineral wool must be contained with a frame. While this may seem nitpicky, take a look at this comparison of the same sized fiberglass acoustic panel vs a mineral wool acoustic panel.

A comparison between a frameless and framed acoustic panel.

Comparison Between a Frameless and Framed 48″ x 48″ x 2″ Acoustic Panel

The red part of the mineral wool acoustic panel is the frame necessary to contain the mineral wool and hold it in place. While these two panels are the same size, there is more effective absorption area in the fiberglass acoustic panels because it is frameless. Not only that, the frame of the mineral wool acoustic panel is hard, meaning it is reflective to sound, which is the source of unwanted echo and reverb we are trying to solve with sound absorption! So while the mineral wool acoustic panel will be very effective at sound absorption, the fiberglass option is simply better because of the lack of frame due to fiberglass being semirigid.

3. Foam

Whisperwave® Ribbon Acoustic Foam

Whisperwave® Ribbon Acoustic Foam

Of all sound absorbing materials, I consider fiberglass, mineral wool, and foam to stand out above the rest. Foam is a material made up of polymers, typically polyurethane, that form a structure of cells. Open-cell foam is superior to closed cell as this allows sound to penetrate as it does into the fibrous fiberglass and mineral wool materials.

The main difference between foam and fiberglass/mineral wool is its density. Foam is less dense, which makes it less effective at absorbing the energy from low frequencies. If this isn’t a concern, then foam is a great choice because it does have the benefit of being more lightweight and thus easier to install. It is also cheaper. For example, AlphaSorb® Pyramid Acoustic Foam is an excellent sound absorption product for applications lacking the need for low frequency absorption. Another great application for foam is in the use of suspended sound absorbing ceiling clouds, like the Whisperwave® Ceiling Cloud.

4. Wood Fiber

AlphaSorb® Wood Fiber Acoustic Ceiling Tile (23-3/4" x 47-3/4" x 1")

AlphaSorb® Wood Fiber Acoustic Ceiling Tile (23-3/4″ x 47-3/4″ x 1″)

Wood fiber is an interesting material that has effectiveness at sound absorption without the synthetic complexity of fiberglass, mineral wool, and foam, although this comes at the cost of being less effective than those materials. Even still, they provide great sound absorption for the right application and are eco-friendly and cost-effective. I happily recommend AlphaSorb® Wood Fiber Acoustic Panels to customers where this material fits their inclinations and applications. Wood fiber is also a great choice when looking to utilize ceiling tiles as sound absorbers, and the material has the benefit of a neat, biophilic aesthetic.

5. Traditional Fabrics: Wool, Cotton, Velvet

While the above four are industry-grade sound absorbing materials, it’s worth noting other materials that are useful sound absorbers, whether on their own for applications that need just a bit of sound absorption, or to help carry some of the load. Traditional textiles like wool, cotton, and velvet by their nature have intrinsic sound absorption capabilities and can help absorb sounds in rooms where they are featured covering furniture, as window curtains, or even as textile art pieces.

6. Synthetic Fabrics: Microfiber Suede, Polyester, Modacrylic, Olefin

Guilford of Maine Metallation

Guilford of Maine Metallation

In addition to traditional textiles, the advance of materials science and related manufacturing has produced a number of useful synthetic fabrics for a wide-variety of uses. Acoustic suede is one that is sometimes utilized in acoustic panel covering or other wall covering applications, providing a measure of sound absorption as a secondary benefit. Some are even engineered for specific sound absorption applications, like SoundSuede™ Fabric. Olefin, polyester, and modacrylic are synthetic fabrics used routinely in curtains, carpets, draperies, and wall coverings that offer sound absorption as well. When looking at such products, it may be useful to select ones with these materials to gain a slight boost to your room’s acoustics.

7. Semi-Synthetic Fabrics: Rayon, Acetate, PVC-Coated

AlphaSorb PVC Baffle/Panel in Grey

AlphaSorb PVC Baffle/Panel in Grey

Finally, we have semi-synthetic fabrics that are either made up of materials like cellulose from wood, a natural material, such as Rayon and Acetate, or coatings like PVC. Again, while these materials aren’t going to be sound absorbers by themselves, when selecting products they are utilized in, it’s beneficial to know they carry some sound absorption capabilities that may help to enhance the acoustics where those products will live.

Find the Best in Sound Absorption Materials with Acoustical Solutions

At Acoustical Solutions, we pride ourselves at offering the highest performing sound absorption products and solutions, which is why we rely on fiberglass.

Our industry-leading line of acoustic panels are up to any challenge while also looking fantastic, thanks to the best in acoustic fabric coverings. In addition, we offer numerous application-specific sound absorption products, like our AlphaSorb® PVC Plastic Acoustic Panels, to make sure no application goes without.

To learn more about the power and effectiveness of our fiberglass acoustic panels and related products, reach out to me today!


To learn more about how Acoustical Solutions can solve your noise control problems, use our contact form, call one of our Acoustical Sales Consultants at (800) 782-5742, or visit us on the web at acousticalsolutions.com.

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