The best sound absorbing materials – such as acoustic foam and mineral wool – do a good job of reducing reverberations and echoes.
If you want to improve the audio experience in your home theater or studio, create a quiet office space, or just generally reduce noise in your property – read on to learn more about sound absorbing materials.
Not all sound absorbing materials can block sound, and as such, not all can be called soundproofing materials. However, they will reduce how much noise travels in an enclosed space, stopping sound waves from bouncing off hard surfaces like floors and walls. This can reduce the overall level of noise in your home or workplace.
A guide to sound absorbing materials
In this article, we’ll get right to the bottom of what the best sound absorbing materials are. We’ve listed our top 4 sound absorbing materials.
We’ve looked at the science behind what makes a good sound absorbing material, explaining why they can reduce noise effectively in your property. This guide will also highlight factors to consider when you are choosing a sound absorber and round up some other sound absorbers outside our top 4.
Skip to:
- What makes a good sound absorbing material?
- Top 4 sound absorbing materials
- How to choose a sound absorber
- Alternative sound absorbing materials
What makes a good sound absorbing material?
It’s simple really; sound absorbing materials absorb – more than reflect or transmit – sound waves. Some materials have more sound absorbing ability than others.
How effective a sound absorbing material is will depend on its efficiency in trapping sound waves and then deforming them.
Many sound absorption materials are soft or porous (have holes in them), allowing them to trap sound waves and dampen sound. So how does this ‘dampening’ of sound work?
According to an academic article by Chinese researchers on ‘Porous materials for sound absorption’:
“Sound absorption materials are composed of channels, cracks or cavities which allow the sound waves entering the materials. Sound energy is dissipated by thermal loss caused by the friction of air molecules with the pore walls, and viscous loss bring by the viscously of airflow within the materials.”
This is how sound absorbing materials can decrease noise and reduce echoes. We should reiterate that sound absorbing materials do not block sound in the same way as a soundproofing material. What they are doing is absorbing sound waves, transforming the energy, and reducing the effect.
Sound absorbing materials can be very effective in improving the acoustics in your home or workplace, with less echo and less reverberation.
We’ll come on to how to select the best material for sound absorption later in this piece (skip to ‘How to choose a sound absorber’ section). But before we display our top 4 sound absorbing materials, let’s have a look at the stats…
NRC of sound absorbing materials
There is such as thing as a ‘sound absorption coefficient’ rating. This can tell us the sound absorption ability of materials, but there are many variables. For example, although a material might have a high sound absorption coefficient, absorbing a lot of sound – but they can also transmit sound to varying degrees. Different sound frequencies can also affect the sound absorption coefficient. Without confusing the issue – a sound absorption coefficient rating does not always reflect the noise reduction ability of a material.
So instead, let’s look at the noise reduction coefficient (NRC) of some common sound absorbing materials. Remember, NRC ratings range from 0 to 1.0. An NRC rating of 0.4 means that a material will absorb 40% of the sound that hits it (and reflects 60%).
Bear in mind – these are approximate figures as the thickness of a material can influence NRC.
| Sound absorbing material | NRC rating |
| Mineral wool | up to 0.9 |
| Polyester fiber | up to 0.9 |
| Acoustic foam | up to 0.8 |
| Cork | up to 0.7 |
Top 4 Sound Absorbing Materials
Let’s run through 4 of the best materials you can find for sound absorbing. We’ll explain why they are good and suggest ways you can use them:
#1 – Mineral wool for sound absorption
Versatile and effective, mineral wool is an insulating material that is manufactured from minerals or natural rock, including mineral slag, basalt (a type of rock) and diabase (another type of rock).
For sound absorption, mineral wool can be used as a filler material in the cavities of your walls, floors, and ceilings.
Mineral wool is an excellent sound dampener, absorbing a large amount of sound energy to reduce echo and reverberation. This is due to its high density and fiber matrix. It is proven to absorb a wide range of sound frequencies, and this ability to absorb high and low frequency sound is one of the reasons it is commonly used in the construction of buildings to improve acoustics and prevent noise pollution.
You can install mineral wool in your home or workplace post-construction, but this would typically involve adding another layer of drywall or removing then refitting ceiling tiles.
Mineral wool also has several other advantages besides sound absorption. It is also used for thermal insulation, as it restricts heat transfer. That’s another reason it is a popular construction material used in residential, commercial, and industrial settings. Furthermore, mineral wool is fire resistant.
Mineral wool is sometimes known as rock wool or stone wool. You’ll usually find it in boards or batts that are ideal to be used in construction.
#2 – Polyester fiber for sound absorption
Polyester fiber is another high-performing sound absorber. It is a synthetic fiber derived from natural raw materials (polyester comes from petroleum).
The fibers of this strong, tensile substance are known for very good sound absorption properties, reducing echoes, reverberation, and noise transmission.
For the purposes of improving sound absorption, you will find polyester fiber in acoustic panels that can be incorporated into the design of your home studio, office or workplace.
Polyester fiber is best at absorbing medium to high frequency noise. This makes it good for absorbing sounds such as audio from music, television or other electronic devices, as well as voices. It doesn’t pick up low frequency noise – such as bass from music or construction noise – as effectively.
You’ll find polyester fiber in panels of various shapes and sizes. They have the advantages of being flexible and lightweight, making them easy to install. You can buy polyester fiber panels that are self-adhesive, meaning you just need to stick them on your wall, floor or ceilings.
Other benefits of polyester fiber include their durability, moisture resistance, and the fact that they are non-allergenic.
And cost… polyester fiber is available at affordable prices.
#3 – Acoustic foam for sound absorption
If you are a music or sound person, or have ever seen photos of a recording studio, it is likely that you have seen acoustic foam. It’s the black or grey foam that often comes in panels shaped like an egg carton, or a series of wedges.
Acoustic foam is made from open-cell polyurethane (an organic polymer) foam which holds many air bubbles. Its small cells are unsealed, allowing air to fill the space. In this way, acoustic foam improves sound quality by reducing the amount of sound that reflects off surfaces. By absorbing sound like this, it can improve the acoustics in a space, reducing echoes and reverberation.
Not only can acoustic foam improve the acoustics in a room – reducing echo and enhancing the clarity of sounds – but it can also contribute to a quieter environment.
Like the polymer fiber panels we’ve talked about in the section above, acoustic foam panels are easy to install. They often come with self-adhesive backing which means they can be stuck easily to the wall. Because the material is so soft, they are easily cut to size if required. They are also lightweight, flexible, and are another good value option for your acoustic performance needs.
#4 – Cork for sound absorption
This all-natural option still has a pretty good NRC rating, although it may not be as effective as the materials above in this list for sound absorption.
If you don’t know and have ever wondered – cork is made from the bark of the cork oak tree. It is a good sound absorber due to its composition of tiny cells filled with air; which do the job of trapping and dissipating sound waves.
Cork is an effective sound absorber, taking in 70% of sound transmitted through it, and reflecting 30%. Its NRC rating of 0.7 puts it behind mineral wool, polymer fiber and acoustic foam, but not by much. If your cork panels are 3mm thick or more, they can provide decent noise reduction.
But cork doesn’t only absorb and dampen sound; it deadens it too. This makes it a viable material for soundproofing, as well as sound absorption, for improving acoustics.
Other advantages of cork include its low weight, and availability in panels which are convenient to install in walls, flooring, and ceilings.
If you are remodeling a home or workspace for better acoustics or soundproofing, cork can be a good option for floor underlayment or insulating walls next to a sheet of drywall. You could also install cork tiles or sheets on the outside of your walls. But they might not look great, and polyester fiber or acoustic foam could be a better option for a home studio due to its superior absorption.
How to choose a sound absorber
We’ve presented you with the best sound absorbing materials, so how to choose the best material for your needs?
Sticking to our mantra of keeping advice simple – we’ll break it down as follows:
👉 If you are building or refurbishing a home, recording studio, or workplace, mineral wool is an excellent choice for sound absorption. It can be installed as a filler in the cavities inside your walls, flooring, and ceiling. In this way, it acts as an effective sound dampener, reducing echoes within a room while also offering some soundproofing capabilities.
👉 If you want to improve acoustics within a recording studio or another space without undertaking any building work, acoustic foam panels are a sensible choice. They are cheap, can easily be cut to size, and don’t involve modifying your property.
👉 If you need a more comprehensive sound absorption solution for a room to cut out high frequency noise such as voices and audio from electronic devices, polyester fiber can be a sensible choice. It may be pricier, but this material possesses a higher NRC rating than acoustic foam. It also comes in panels that can be stuck to the outside of a wall, with a more attractive look than the ‘egg carton’ design of acoustic foam.
Alternative sound absorbing materials
We gave you 4 of the best sound absorbers, but while we’re on the subject, there’s an opportunity to look at some alternatives.
Here are a few other sound absorbing materials you might want to look at:
Sound absorbing curtains
Sound absorbing curtains – also advertised as soundproof curtains – do a good job of improving room acoustics, and absorbing sound waves. They are usually heavy curtains that extend from the ceiling to the floor. A handy temporary sound absorption option that is easily removable when required. Read our round-up of the best soundproof curtains here
PVC panels
PVC is another material in which you will find acoustic panels. It is a useful sound absorber often used for ceiling tiles, reducing echoes and reverberation. PVC are water resistant, fireproof and durable, and can be used in the interior of structures during construction, or installed externally post-construction. A decent acoustic foam alternative for recording studios.
Sound blankets
Heavy blankets are great sound absorbers. You don’t even need to buy blankets specifically designed for sound absorption. The heavy moving blankets used to protect furniture during transit will do. But below we’ve picked out a sound blanket you might want to consider for your recording studio, office, or other quiet space. See more information on sound blankets in our article on ‘How to Soundproof Vents’
