The first thing that is important to do here is to identify the difference between sound proofing and sound absorbing. They are two completely different things and we are talking about the latter here.
Sound can either be absorbed (sound absorbing) or reflected away (sound proofing). If your issue is with unwanted noise entering or leaving your space, then you need to look into soundproofing.
Sound absorption is a technique to improve the acoustics of a room and reduce echo, thus giving you clear audible sound within that room.
Sound absorption works by sound waves losing their energy as they are absorbed by materials that are used on the walls, floors and ceilings of a room. This reduces the echo within a room and therefore increases the sound quality within that room. It doesn’t completely prevent the noise from being audible in another room as it only reduces the echo and doesn’t block it.
Why Would I Need Sound Absorption?
Aside from a living space being much more pleasant to live in, there are situations where sound absorption is necessary.
For example recording studios, lecture auditoriums, concert venues, theatres, sports halls, cinemas and school gymnasiums all use sound absorption to improve the quality of sound within that space. Imagine trying to record something in a recording studio and constantly having sound reverb and echo around the space. It would make for pretty poor recording quality.
What Makes A Good Sound Absorbing Material?
According to Mike from soundproofing solutions provider NoisestopSystems “A sound absorber or diffusor would typically be something that is soft, light and/or porous as these types of materials will be able to absorb echo. “
A porous absorber is, as the name suggests made of porous material. There are two types:
Fibrous material absorbs sound waves as they can penetrate the surface where they will be bent, dampened and converted into heat energy. Only small parts of the sound waves are reflected back into the room.
Open-celled foam absorbs sound by sound waves moving through the air and passing through the passages of the material. This reduces the sound and generates heat.
Porous absorbers are highly effective in reducing mid-range sound frequencies, plus the thicker the material the greater the sound absorption.
Panel absorbers are made of non-porous flexible material and are generally used for lower bass frequency sound waves. These acoustic panels can effectively absorb sound waves, but again, not all panels are created equally, so check before buying that they are suitable for your purpose.
A resonance absorber contains a mechanical or acoustical oscillation system. This system comprises of plates with an airspace and are either made of perforated materials or have a hole/opening in them.
The plates openings are able to trap sound waves inside and reduce the echo and are most effective on low frequencies.
It is important to do your research as the overall effect you want will be to improve the quality of sound within your space. There are many different sound absorbing materials on the market, so you want to make sure that you aren’t wasting money on half-way or ineffective solutions.
Not all sound is created equally and not all sound absorbing materials absorb equally either. Low frequency sounds, below 500Hz may be a lot more difficult to detect and therefore to absorb. Higher frequency sounds, above 500Hz are far easier to detect and absorb.
The other important thing to note here is that you may need multiple sound absorbing materials and sealants to receive the desired effect.
So here is a quick run down on the top 5 sound absorbers…
1. Acoustic Foam Panels
Acoustic foam is both easy to install and relatively affordable, plus, it is one of the most effective materials for sound absorption.
The foam comes in a variety of fabrics and designs, which also makes it an aesthetically pleasing addition to most areas. The best use of these panels is for small to mid-sized spaces such as recording studios and offices.
A convoluted acoustic foam panel has an egg crate design that you will typically find being used in recording studios.
Fabric covered foam panels are great for improving acoustic performance everywhere and are often used in auditoriums and theatres.
Aluminium facing foam panels are designed to be used in spaces that need protection from heat as well as sound absorption.
2. Acoustic Fabric Panels
These wooden framed panels are wrapped in fabric with a sound absorber inside such as foam or high densityfibreglass.
The fibreglass panel is usually used when dealing with low frequency sounds as it is known as a bass trap.
Fabric wrapped acoustic panels are so effective at controlling echo and reverberation, that you only need a thin panel. The choice of colours and patterns also contributes to the aesthetics of these panels and they can easily be incorporated within your design and décor.
3. Sound Absorbing Underlay
Sound absorbing underlay may be made out of acoustic foam, felt, rubber, vinyl or even plywood and the density of the material is what helps with the sound absorption.
This underlay is typically added between sub-flooring or under flooring such as hardwood or laminate. They can also provide a level of soundproofing. The overall effect is to soften the sound within the room, but it can also prevent sound travelling between floors.
4. Acoustic Partitions
An acoustic partition is available in either lightweight or heavyweight material and is usually made of polyester.
Lightweight partitions are designed to be mobile and act as a room divider to create a quiet area, say, within an office. They come in a variety of colours and to fit with the design of your space.
5. Acoustic Ceiling Tiles
These are fitted directly to the ceiling or to create a ‘false’ ceiling. Much like the underlay, these panels help to absorb sound between floors, but also create better acoustics in large open spaces such as lecture halls.
Acoustic ceiling tiles are available in a wide variety of sizes, depths and designs as well as a few different materials.
Our advice is to always think about what type of area you have, what type of sound quality you require and what you currently need to correct. If you have any questions about the best way to proceed in improving the quality of sound within your space, we would suggesttalking to an expert. Even if you go down the DIY route, you could save yourself a lot of time and money if you know what you are looking for in the first place.