Do you know the difference between soundproofing and sound absorbing? Most people assume they're the same thing, but in fact they are different techniques. In this blog, we look at both approaches to controlling sound and take a look at them in more detail.

What's the difference?

Sound is made up of vibrations that travel in waves. When they hit a hard surface, like a wall or ceiling, they bounce back off - what we would call an echo or reverberation. There are two different types of sound waves and both are equally important.

Airborne noise - sound waves that travel through the air, such as the noise of a TV

Impact noise - the vibration caused when two surfaces meet, like heavy footfall

Soundproofing attempts to stop noise from entering or leaving a space. Whereas sound absorption is about reducing the amount of echo (or reverberation) in a space. Though this will cut down on the amount of background noise, it won't stop it completely.

Both techniques are useful in their own ways, but which one you need depends on how you intend to use a space and what you want from it. Let's delve a little deeper into the difference between soundproofing and sound absorbing.

Soundproofing in detail

Sound can travel into adjoining spaces (your neighbour’s house, for example) through partitions like walls, floors, and ceilings. Most standard construction materials are only able to stop a limited amount of noise transferring from one side to the other.

A wall, for example, might stop 45 decibels of sound travelling through it. But in practice, this means you'd still be able to hear loud noise, like music, coming from the other side.

There are lots of reasons you might want to stop noise from entering or leaving a space, and with the right soundproofing techniques, this is possible.

1. Insulation

Most partitions between adjoining spaces have cavities in them, and when sound makes its way into these gaps, it reverberates around and the noise is amplified. The first step to soundproofing a room is to fill this gap with insulation. You can do this with acoustic mineral wool, like Muffle Wool, which is not only good for sound insulation but it also has thermal properties and is fire resistant.

2. Adding mass

Adding mass to your partition walls, floors, and ceilings, is an effective way of stopping the transfer of noise. High density materials like acoustic plasterboard can be layered with insulation and an acoustic membrane, to stop different frequencies of sound.

3. Decoupling

Mass is a great way of dealing with airborne noise but it's not as effective at stopping impact noise. To stop vibrations travelling between adjoining spaces, you need to create a break between your wall and the solid structure behind it - known as decoupling.

You might have heard this referred to as a 'room within a room', but it's not as drastic as it sounds. A clip and channel system can create a small but effective gap between your new wall and the solid partition that separates you from the people next door.

Now that we understand a bit more about soundproofing, let's move on to absorption.

Sound absorption in detail

Sound absorption is about cutting down on noisy echoes that can make a space feel unwelcoming. Acoustic panels made from absorptive materials convert sound energy into heat, and stop it from being projected back into the room.

It is possible to measure the amount of reverberation in a room using a calculation known as RT60 (RT = reverberation time). Put simply, this is the amount of time it takes for a sound to reduce by 60 decibels, or for the sound to disappear.

The perfect reverberation time depends on how you intend to use the space - what works for a music venue would be no good in a library!

  • Less than 0.6 seconds is considered acoustically dead
  • More than 2 seconds is considered too 'echoey'

Absorption products come in a wide variety of sizes, shapes and styles to suit different spaces, from classrooms, to offices, restaurants, and hotels. This includes:

We also sell furniture, lighting, and other acoustic accessories that not only absorb sound but are functional and look great in any space.

When you're choosing acoustic products, look out for its absorption rating. This number between 0 (no sound absorbed) and 1 (all sound is absorbed) is known as the noise reduction coefficient, and it can help you evaluate how effective a product is.

Choosing the right technique

Soundproofing and sound absorption are distinct techniques, but how do you know which one is right for your project? Start by asking yourself, what the problem is:

1. Is the space too loud?

2. Is it too echoey?

3. Is it letting noise in or out?

If it's too loud, or full of distracting and unhelpful echoes, then sound absorption products can help. Reverberations in a classroom, for example, can make it difficult for students to hear each other and their teacher, so in this case absorption is critical.

However, if your space is letting too much sound in or out, then you'll need to consider using the soundproofing techniques we've covered in this blog. A home cinema or music recording studio, for example, both need to be completely soundproof.

Every space is different and requires a different approach to managing sound. But we don't expect you to be the experts in soundproofing and absorption, because we are.

The friendly team at Muffle can guide you through the different techniques, and find the right products to suit your needs, whether you're a private customer with a home renovation project, or part of a team working on a new commercial fit-out.

We've hand-picked products from leading manufacturers across the globe to create a one-stop shop for acoustic solutions. All you need to do now is browse and click!