Sound Absorbing Materials: The Complete Guide

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Silent Home Hub Sound Absorbing Materials

There’s a misconception in the air when we talk about soundproofing and sound absorbing. The former’s ultimate goal is to prevent sound transmission. The latter, to reduce reverberation and to improve the sound quality in a room.

These two yet complement each other. If your main noise problem is the amount of echo and reverberations in a room, this article is for you!

Table of Contents

Types of Sound Absorbing Materials

Soundproofing materials stop sound waves from entering or leaving a room. These materials are usually dense and heavy.

The process of soundproofing involves: adding mass, damping, decoupling, and absorbing. Thus, sound absorption is a part of soundproofing.

You will find a lot of sound absorbing materials in soundproofing methods. One option would be acoustic foam panels for your walls. Audiophiles can vouch for both to work hand in hand to achieve the desired result.

Sound absorbing materials absorb sound waves that collide with them and minimally reflect it back. This quality greatly improves the acoustics in a space.

There are a lot of materials available for sound absorption. Their ability to absorb sound waves depends on frequency, composition, thickness, and mounting method. Scientifically speaking, there are three main types of sound absorbers:

1. Porous Absorbers

Energy is not created or destroyed. It is only transformed. A fundamental concept of energy and matter we use in our day-to-day living.

Porous absorbers convert sound energy into heat energy through friction and viscous resistance. This then passes through the fibrous or cellular structure of its materials.

These porous absorbers are permeable. It allows sound waves to penetrate its surface.

During this process, the amount of heat energy generated is minimal. Less than one-millionth of a watt! Only a small part of the sound energy reflects back. The result is reduced echo and reverberation.

These porous absorbers have a high sound absorption coefficient. They are best for mid-range frequencies and treble tones.

You’ll find many examples of porous absorbers in the market today.  These are:

  • Different textiles
  • Fleece,
  • Carpets
  • Acoustic tiles
  • Acoustic (open cell) foams
  • Insulation curtains
  • Cushions
  • Cotton
  • Mineral wool, such as fiberglass

Most of the materials we will discuss fall under this category.

2. Membrane or Panel Absorbers

A membrane absorber is a non-rigid and non-porous material placed over an airspace.

The oscillation system is the mass of the front panel and the spring formed by trapped air. This process happens when sound energy is applied to the absorber. This transforms it into mechanical energy.

These membrane absorbers are solid in appearance. Because of this, people often overlook their capacity to absorb a sound wave.

They are most effective against low-range frequencies, such as bass. But they also reflect higher frequency sounds. A combination of other forms of soundproofing and absorbing will give you better results.

Common examples of membrane absorbers are:

  • Hardboard paneling
  • Suspended plasterboard
  • Windows
  • Wood doors
  • Gypsum boards
  • Wood floors

Tables, chairs, closets, and other bedroom furniture function as panel absorbers too.

3. Resonance Absorbers

Resonance absorbers work similarly with membrane absorbers. It also consists of an acoustic oscillation system.

There is a solid plate on the front with tight air space behind it. It works based on sound pressure. Resonance frequency adjusts depending on the mass of the front wall, or the spring’s thickness.

An example of sound absorbers would be layers of perforated plasterboard. They’re also referred as perforated metal corrugated sheets.

The perforations (holes) act as the bottleneck, trapping and locking sound into the space behind the sheets.

What Are The Best Sound Absorbing Materials?

These 10 best sound absorbing materials are used both professionally and for DIY. Each does a great job improving the acoustics of a room, reducing echoes and reverberations.

Some are better than others, and some require a combination of two or more solutions. These materials often add extra value to your home too. Mainly for aesthetic and decor.

I will explain these in detail. I hope it helps you make a sound decision that best suits your soundproofing needs.

1. Acoustic Foam Panels

When we talk about porous absorbers, the first thing that comes to mind are acoustic foam panels.

These are made of soft and porous materials that feature notches or cups. It’s perfect for dampening sound within a commercial or residential area. You can surely use them to keep sound out.

Installing them on walls, doors, or ceilings prevent sound from hitting hard surfaces. Instead, this traps them inside the foam. This way, effective soundproofing, and sound absorbing results in a room.

  • Musicians
  • Podcasters
  • Gamers
  • Home theatre lovers

They usually come in packs of 4, 6, 8, or 12. You’ll surely have the right number for your needs. They’re inexpensive too!

These soundproofing foam panels come in many sizes and colors. Many homeowners like to choose different colors.

A creative idea is to place them in unique patterns on the wall assembly. It’s a great way to improvise visual appeal to your homes or home studio.

Apart from that, you will notice different thicknesses, shapes, and foam patterns. Some are shaped like egg cartons, waves, mazes, and many others. Shapes don’t necessarily affect their sound absorbency. Thickness does. The thicker the material, the better.

Acoustic foam panels are extremely easy to install. There are ones that come with peel-and-stick backing for extra ease.

If they don’t come with an adhesive strip, use 3M command strips, hook and loop strips, or spray adhesive. Conveniently mount the materials on your walls and ceilings.

If you plan to move these foam panels, use removable adhesive strips to ease removal and avoid ruining the wall.

These are perfect just about everywhere. You can use them in the comforts of your home, in offices, and in recording studios.

Bigger spaces use a lot of these materials too. You can find them in auditoriums, theaters, gymnasiums, and manufacturing facilities.It’s number one on our list for its ability to improve acoustics and to keep sound out. It is also very affordable and can double as wall art.

2. Acoustic Partitions

Another product great for sound absorption is an acoustic partition. Note they may not offer much in terms of noise blocking.

These are often large pieces placed in the middle of an open room. They have a similar effect, as if you were rearranging soft furniture. These partitions are ideal when you want to divide a room into compact spaces. You save a lot of time, cost, and the trouble of remodeling.

Acoustic partitions are made of strong structural materials. They are covered with thick porous fabrics that give it its sound absorbing qualities.

There are foam partitions, and some made of materials like polyester or cotton too. These essentially stop sound waves from traveling around the room.

You probably see a lot of acoustic partitions in your daily life. These are the ones being used in corporate office spaces to separate employees from each other. They are useful for separating rooms and cubicles, giving every person the privacy he or she needs.

What’s great about these acoustic partitions is that they are very versatile. They are easy to install and move around.

You can opt for customization too. They are available in endless size and color options to match any decor. They are highly durable and have exceptional quality.

This is surely a great investment for:

  • Offices
  • Study areas
  • Conference spaces
  • Restaurants
  • Any space you wish to divide to enjoy quality sound

3. Wood Wool

Mineral wool boards are made of wood wool, which are ecologically simple to produce. They are mixed with binding agents such as cement and gypsum.

Cementitious wood wool panels are eco-friendly, high performing, and cost-effective. They contain 70% recycled content and cost less than fiberglass.

Mineral wool materials are great thermal and sound insulators. They effectively reduce echo and reverberation through sound absorption. They are installed on ceilings and walls much like the ones on recording studios.

Wood wool boards come in many sizes and colors that transform the aesthetics of the interior space of every room. They can complement any decor!

4. CFAB Cellulose Panels

CFAB cellulose soundproofing insulation products are sustainable and environmentally responsible. They are made of 65-75% recycled and renewable fibers. It is the first of its kind in the industry!

The open design and density of the CFAB cellulose sound proof insulation panel increase sound absorption and deadens sound energy. The STC ratings on this exceed the values attained by most acoustic foam panels. They are easy to handle and install. It resists mold growth too. If you’re looking for “green qualities” in soundproofing materials, this is the most earth-friendly and cost-effective option.

5. Acoustic Window Film

Windows are a common source of noise leakage. After all, glass is highly conductive and reflective of sound. It causes a lot of echoes and vibrations. Windows are often made of thin glass and make poor sound barriers.

Acoustic window vinyl film adds to the density of the window. Thus help reverb and absorb sound. Exact features differ between brands and products. The right one can make all the difference to the fragility of your window.

Single pane windows are often sensitive to movement and cause a vibration sound. Ideally, adding glass acrylic panels would solve your sound problem. All the more if you shift to double or even triple-pane windows.

But if you are on a budget, these window films made of vinyl can certainly absorb some of the sound impacts.

To improve sound absorbing performance, use window vinyl films with another type of solution. Soundproof curtains or other forms of soundproof insulation work best.

6. Acoustic Bass Traps

Acoustic bass traps are in essence made of the same materials as acoustic panels. They are meant to be used in tandem.

Bass traps control and help tune the low frequency sound of a room. It breaks up the sound and soaks up any excess bass, leaving you with a clean sound output.

They come with a high noise reduction coefficient (NRC rating). Bass traps effectively improve the acoustics of a room, especially for recording music.

Bass traps have two flat sides at a 90-degree angle. One fits into the corners of the room, and the other faces the room.

They are often available in trapezoid shapes to best fit these wall corners. You can even customize some to have images on them as wall decor.

Having acoustic bass traps installed give the most optimal conditions for your home theatre or studio.

7. Acoustic Hanging Baffles

If you have little wall space, this is the solution for you.

You can hang acoustic baffles from the ceiling and create soundproofing insulation.

These hanging baffles work well for those who prefer a discreet approach to soundproofing. They are designed to improve sound quality in spaces of all sizes.

They work perfectly for auditoriums, call centers, offices, or anywhere with limited wall space.

They are made of high-quality acoustic foam that offers superior sound absorbing capacities.

They are easy to install with medium to light-duty chains and hooks. You don’t have to worry about acoustic backing or modifying the walls of your space since these boards suspend in the air. Hanging baffles add art to your interiors too. You can opt for a custom fabric covering to complement the overall aesthetic of your room.

8. Acoustic Curtains

Soundproof curtains are one of the most attractive soundproofing solutions out there! They are made of materials thicker and denser than your regular curtains.

READ MORE: Best Soundproof Curtains for a Quieter Home

Thermal blackout curtains have tight weaves and are effective noise blockers. Their triple-weave technology allows optimal soundproofing.

Acoustic soundproof curtains prevent sound from hitting a wall or a window by absorbing them. The quality of its materials are even thick enough to block some frequencies.

You will want to buy one that is long enough for full wall or window coverage for best results.

Acoustic curtains are a great complement to other soundproofing solutions. They can cover up ones that are less attractive. They are often combined with mass loaded vinyl to dampen sound and reduce echo.

Acoustic curtains are made to improve sound in a room. For more sound blocking, such as for industrial noise, use curtains quilted with fiberglass.

Rockwool layers, sandwiched over MLV, are a good option too.  These are particularly used to control noise from specific equipment.

A different kind of acoustic curtain is also available. These are room divider curtains. They are made to hang in the middle of the room and provide privacy between spaces.These come with the same thick sound absorbing materials. The difference is only its placement and add-on purpose of creating partitions.

9. Moving Blankets

When your budget is tight, these moving blankets come in handy. They do an excellent job absorbing sound in a room and for a cheap price!

Moving blankets are in essence used when moving furniture. Since it is made of thick and heavy materials, their fabric makes it a good soundproofing tool.

Manufacturers eventually figured out musicians and audiophiles used moving blankets to deaden sound. They were quick to rebrand their products as soundproof blankets.

You can hang moving blankets on walls, over windows and doors. Most are made of cotton batting and polyester backing and weigh a little over 5 pounds.

Moving blankets for its main purpose do not contain grommets. But in recent years, manufacturers improved their design to cater to those who use these blankets for soundproofing.

Consider buying those that come with grommets along the sides. It makes installing them a whole lot easier!

10. Foam Gaskets and Green Glue

Gaps between the door jamb and door, are places where unwanted noise can enter through.

It is necessary to seal all the gaps as much as possible. This might seem like it’s not worthy of considering, but trust me, a little can go a long way!

Compressible foam gaskets help seal these gaps and absorb some sound. Pair this with a door sweep to seal the space between the floor and the door.

If your door is not thick enough to block noise from a hallway though, consider pairing it with heavyweight blankets.

Gaps between windows and other soundproofing solutions also allow noise to leak in. To maximize your soundproofing, apply a generous amount of green glue straight out of a caulking gun. Green glue compound along with other acoustic foam tapes and gaskets help diffuse and soften the sound. On their own, they can’t fully solve your sound problem. Combining it with other methods will surely give you better results.

Sound Absorbers Already in Your Home

Did you know some of your household items could already be effective sound absorbers? If you’re on a budget, start your sound absorbing solutions with things you already have access to.

1. Sofas, Cushions, and Pillows

Rearranging furniture is a great way to reduce impact noise levels in a room. Getting cushiony sofas with a bunch of pillows is a plus. Its soft, thick, and the porous material definitely helps reduce noise transmission.

You can even arrange them in a way that adds to the overall aesthetics of your space!

2. Think Carpets and Rugs

A thick carpet and some rugs are great sound absorbers for your walls, floor, and even ceilings.

If you have noise issues with your neighbors, having a thick rug would lessen the vibrations caused by footsteps. You are sure to get better sleep.

If you have extra bucks to spare, a wall-to-wall carpet with a soundproofing underlay would do great for a home office.

For those on a budget, a layer of mass loaded vinyl (MLV) beneath your rugs is a good substitute. They add mass to the floor and aid in the soundproofing between structures.

3. Wall Hangings, Paintings, and Tapestries

Bare walls allow sound waves to easily bounce off and increase in volume. Anything that can cover your walls is going to be handy.

Heavy paintings and tapestries act as a soundproof barrier. The bigger the size and dimension, the better too. Thick cloth and linen tapestries are ideal. They’re highly porous, thus have better absorption qualities.

It’s a good investment! It reduces reverberations and echoes in your space, as well as decorate your wall.

4. Sound Absorbing Egg Cartons

An egg crate is made of paper fibers which are known to be decent sound absorption materials. These egg cartons may not be effective soundproofing materials, but they might just be able to stop sounds from echoing.

Note they cannot do much on their own. Consider filling the crates or combine them with more effective techniques.

It’s not the most pleasant looking solution too. You can opt to conceal them with some fabric upon installation to your walls.

5. Regular Curtains and Blankets

There are special curtains, and blankets with thick fabric specifically made for soundproofing. However, if you have some regular ones lying around, you might as well use those on your walls, windows, and doors.

Note that the thicker the blanket or curtain, the better. You can layer them to be more substantial. They should still effectively absorb sound.

Final Thoughts

Sound absorption is a crucial part of soundproofing. These materials reduce echo and reverberations in any space, improving its acoustics.

There are a lot of sound absorbing materials out there and each day innovation presents itself. I hope you are able to learn a thing or two, and found your answer among these examples.

READ MORE: How to Soundproof Basement Ceiling From Noise