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What Type of Foam Is Best For Sound Absorption?

Jan. 06, 2022

Whenever you’re at a loud concert or want to get a peaceful night of sleep on an airplane, you may find yourself popping a few pieces of foam earplugs into your ears. When you plug these tiny pieces of foam into your ears, you quickly notice that your ability to hear exterior noise diminishes. Why is that, exactly? It’s because foam works wonder at absorbing unwanted sounds.


Much like earplugs, the acoustic foam provides users like you with the noise reduction qualities they desire. These heaven-sent pieces absorb sound so that any noise you generate inside stays in, while external noise remains outside. How does acoustic foam help block out these unwanted sounds?

Open Cell Foam

 Open Cell Foam

Open Celled vs. Closed Celled Foam

To understand how foam reduces sound, it’s important first to learn how to differentiate between the two types of foams that absorb sounds. While both foams provide their own degree of insulation and barriers against noise, their properties distinguish them as two separate products.


Airborne acoustical energy converts to heat and diminishes the amplitude of the noise signal. The power becomes lost in the process, which means it’s essential to choose the soundproofing material that matches the air movement or pressure waves with the right amount of control levels.


Open-cell foam provides a form that allows air to move through the material through porous spots and openings. As the name implies, this foam has open cells that absorb both sounds and liquids by retaining these components into their cell chambers. Unfortunately, their irregular shape means the user often does not have control over the level of sound energy absorbed.


Closed-cell foam is a specific type of foam that boasts a higher R-Value than its open cell counterpart. Closed-cell foam has tightly-woven cells that produce a “closed” effect. Because of this, closed-cell foam results in a denser material that works better at absorbing low-frequency noise.

Closed-Cell Foam

 Closed-Cell Foam

Sound Absorption Through Air Movement

Acoustical energy and airborne energy converts to heat during the process of sound saturation. Sound energy transforms into an absence of noise through absorption that transforms noises into heat, which produces the noise reduction levels you desire.


Air movement, also known as molecular velocity, is what typical insulators and absorbers use to reduce sound. This process consists of air movement through the sound absorbing material that processes heat and essentially absorbs the noise. The amplitude of the sound diminishes and weakens the reflection of the noise and causes a dulled sound effect in the process of sound reduction.


Frequency Breakpoint: Which Type of Foam Makes the Most Sense for Your Needs?

You must first evaluate the need for the room you will be soundproofing to choose the best fit for your noise reduction needs. All foams boast a unique and varying level of performance and benefits that help you to fulfill your different sound and reverberation reduction needs.


Low-frequency waves require pressure-reactive devices such as diaphragmatic absorbers and membrane absorbers to block noise. Open-cell foam provides a cheaper alternative to closed-cell foam that is often enough to fulfill your low-frequency noise reduction needs. For medium- and high-frequency sounds, opt for a closed-cell foam with a higher R-value instead.


Always remember to be conscientious about the foam you choose to get the most out of your soundproofing product.

If you want to get more information about the sound-absorbing foam, welcome to contact us today or request a quote.  

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