How does soundproofing foam work?

17.08.2016

acoustic foam

Asking how acoustic foam works is usually an invitation for a barrage of jargon, science and misinformation, with a minimum entry requirement of a PhD in physics and an unhealthy interest in manufacturing processes. Luckily for you, we’re going to cut through all the noise and tell you exactly what you need to
know about acoustic foam.

Let’s start with the basics

Acoustic foam can be used either to block out sounds from the outside world or to absorb sounds within a room to reduce reverberations. Both have their place, so it’s important to know what you’re trying to achieve before you invest in technical foam.

These days, some form of soundproofing is the norm for most industrial and domestic buildings. Whether you’re in a restaurant, school, open-plan office, gymnasium, church or hospital, they will probably either be designed to control the acoustics architecturally, or they will have acoustic foam installed to reduce background noise and block outside sounds.

Did you know that, according to Julian Treasure, author of Sound Business, open-plan offices can make employees 66% less productive? This is due to distractions and our need to quite literally hear ourselves think. Whether you want to improve sound quality for music production, manage acoustics in large open-plan buildings, insulate against noise from heavy industry, or simply reduce noise from traffic, acoustic foam is probably the answer.

Foams that absorb sound

If you want to absorb sound within a room then you need to soften the hard surfaces. If you’ve ever wondered why ‘cold’ buildings like churches and gymnasiums echo when you clap your hands, it’s because the sound is bouncing off of the walls and ceiling and is then being amplified by the shape of the room.

A common approach to soaking up sound within large rooms is to install soundproofing panels that are cut to size and fitted to the biggest surface areas such as floors and ceilings, as well as connecting areas such as pathways and corridors. This approach is effective at dampening ‘airbourne sounds’, but (you guessed it) there’s more than one type of noise.

Foams that block out sound

Ok, so noise is noise, but the different noises travel in different ways. If your problem is sound coming through the walls and ceilings from adjoining parts of the building, then you will need to soundproof the room. This requires materials with the opposite characteristics from the soft and lightweight foam that you’re likely to see in places like recording studios.

If you want to block out noise then you will almost certainly need to install soundproofing foam inside the wall construction. These are typically dense, heavy panels that are designed to ‘decouple’ the wall between rooms to stop sounds travelling via materials.

A room within a room

This leads us on nicely to the dream world of purpose-built environments that are designed for optimum sound.
In theory, the ‘room within a room’ method creates a completely soundproof area by both absorbing sound inside the room and blocking sound from the outside world. If this sounds crazy and slightly futuristic, then you’ll be surprised by how relatively common this is for businesses that need a highly controlled environment.

To illustrate how time-consuming this kind of venture can be, consider the recent case of the retail store that took two years to complete (yes, you read that correctly). Audio giant Sonos went to painstaking lengths to create the coolest store on the planet for audio geeks when they unveiled their flagship store in the heart of Soho in New York.

Designed by Partners & Spade, the 4,200 sq ft space was kitted out with seven listening rooms, each custom-built and insulated with four layers of acoustic sheet rock for walls and a 2,000 lb steel and bevelled glass door. The result? Audiophile heaven.

So, what else should you know about acoustic foam?

As the UK market leader, we’re always looking for new ways to improve our product range. We currently engineer specific types of foam of varying shapes, textures and thicknesses for almost every situation – from soundproofing foam through to Basotect panels, Class-O fire retardant foams, audio foams, speaker fronts and even microphone windshield foams.

But there are always interesting developments coming out. For example, scientists at the Swiss Federal Institute of Technology in Zurich are currently using theories from quantum mechanics to produce a new material that insulates vibrations rather than allowing them to pass through the foam.

Dubbed ‘super quiet sound proofing’, this new type of material (if successful) could dramatically reduce the amount of material needed to soundproof a room. The most exciting characteristic about this type of foam is that it could allow noise to pass in only one direction – handy for homeowners looking to get their own back
on noisy neighbours!

Practical next steps …

So, this article might not have resulted in PhD-level knowledge of physics, nor will it (we hope) have triggered an unhealthy interest in manufacturing processes, but it should clue you up enough to feel more confident when planning a project that requires acoustic foam.

Our parting advice is to identify the type of sound you want to reduce and assess the architecture of the room where you need to install sound control measures. Trust us when we tell you that this is the fun part – you’re better off leaving the more technical aspects of acoustic foam to professionals and getting on with enjoying some peace and quiet!

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  • John Williams

    Hey, my friend and I are doing a science project and wanted to know like how exactly it worked, such as how the design and material go into making the foam more effective than other types

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