Soundproofing can be a mystery to the average consumer. What exactly is it? Do I need it? How can I tell? Yet it’s usually fairly clear if we have acoustical leakage problems, because they’re often annoying, embarrassing, or unprofessional. In order to help you understand soundproofing, and how you can tell if you need it, we’re publishing this introduction to soundproofing, a beginner’s guide. 

Being Certain About the Problem

The first thing you need to establish is whether you actually need soundproofing, or if you just need sound absorption. While soundproofing is a method of preventing sound from traveling between two spaces, sound absorption helps to reduce noise coming from within a single space.

So, if your problem is noise bouncing around and ruining the atmosphere within a single space, then what you actually need is sound absorption, which involves placing sound-absorbing elements such as wall or ceiling panels around the space.

On the other hand, if your problem is sound within a room leaking out, or sound outside leaking in, then soundproofing is indeed the solution you’re looking for. This can be in a home where sound travels too easily between walls, in an office where sensitive conversations are audible outside in adjacent rooms, or in various other professional spaces, like sound studios. 

Soundproofing Principles

There are a few different factors which affect to what extent sound travels between spaces, and they have to do with the physical properties of whatever separates those spaces, which are generally walls. 

Mass

Materials with a lot of mass naturally block sound, because the more dense matter is there, the more there is to absorb the sound. Drywall makes up the surface area of most walls and ceilings, and has some sound-absorbing properties, but often not enough. 

Damping

We’re all familiar with the experience of touching a resonating surface of object, such as a guitar string, and stopping it’s vibration and sound. Well, part of the reason walls often allow so much sound through is that they resonate in a similar way. One solution to reducing this is to damp the walls, usually with specially designed acoustical glues which are applied between layers of wall material, in soundproofing projects. Damping is especially good for reducing low vibrations, such as music with a lot of bass. 

Absorption

There is an element of sound absorption in soundproofing, which is that sound-absorbing materials are often included in the layers which are added within walls, to block/absorb the sound. 

Layering Between Barriers

The primary method typically employed to soundproof walls and ceilings is to remove the drywall, and add soundproofing layers to the interior of the wall structure. These layers can consist of many types of materials, but generally will be combinations of materials with mass for sound blocking, and other materials with more sound absorbing qualities. 

We’ve written more extensively about how to soundproof a wall here