Soundproofing works by tackling the two ways in which sound travels; through the air (airborne noise) and through physical things via vibrations (impact noise).
What is Soundproofing?
The dictionary definition of soundproofing is “to prevent sound from coming into a room or building, or from being heard outside it”.
The golden rules of soundproofing are:
- If air can get through then sound can get through.
- Minimise vibrations as much as possible.
Soundproofing is all about making amendments to the physical structure of a property so that vibrations and airborne sound are dispersed and absorbed efficiently.
The golden rules of soundproofing are; If air can get through then sound can get through & Minimise vibrations as much as possible.
There are four primary methods that are used to effectively Soundproof:
- Adding Mass
For the best results a combination of all four methods should be used.
How Does Dampening Work?
If you ring a bell and then touch it with your hand the ringing sound will instantly stop, this is how sound dampening works in a soundproofing project.
Noiseproofing compounds are used to dampen vibrations, these work by turning sound energy into heat.
Compound will be added in areas which vibrations typically travel through such as floor panels, the compound will be tightly sandwiched between the floor panels (or drywall panels).
When sound waves travel through the panels it creates shearing forces between the stiff panels creating friction in the layer of compound where the sound energy is then turned into heat.
How Does Adding Mass Work?
Adding mass is the most effective methods of to soundproof.
The mass you use can be made up of a huge range of materials, in the soundproofing industry it is typical to use things like mass loaded vinyl, soundboards and dense insulation foam to add mass.
One of the problems with using mass to block sound is that adding mass will take up more wall space meaning that the size of a room will be marginally reduced.
Mass is very effective at blocking airborne sounds however it is not so great at blocking impact sounds.
How Does Decoupling Work?
Decoupling is a soundproofing method which involves deliberately creating gaps within a wall to prevent vibrations carrying through it.
Decoupling is one of the most effective ways of soundproofing a room and is the method behind the room in a room strategy of soundproofing which is said to be the most effective soundproofing method.
Decoupling can be a very expensive procedure if it is being implemented in a pre-existing structure, however if you are planning a new building it is well worth using this method.
It is important when you undertake a decoupling project that you combine it with other methods such as using high density insulation to avoid creating an echo chamber in the wall cavity which could amplify airborne sound if due care is not taken.
How Does Sound Absorption Work?
Absorption is commonly used to reduce echo and improve sound quality in recording studios and cinemas.
They work by dissipating sound energy as heat. Absorbent acoustic tiles are the easiest method of soundproofing a room however it is also the least effective method.
Soundproofing Against Airborne Noise
Airborne noise is noise that is transmitted through the air. Someone talking, a radio or TV playing are examples of common airborne sounds.
Airborne noise can be a problem in homes where you have thin internal walls which are poorly insulated and have gaps in them (for example around plug sockets).
The lack of insulation means the sound can travel freely through the gaps in your wall without being absorbed.
Dealing with airborne noise effectively involves dampening and adding mass. This is done by sealing up walls, doors, floors and ceilings (walls are usually the primary culprit) and adding insulation to prevent airborne noise from travelling through.
Soundproofing Against Impact Noise
Impact noise is noise that occurs when an impact is created and the vibrations carry it through a building.
Examples of impact noise include someone walking heavily on a floor, hammering, doors closing or furniture being moved about.
Impact noise is often a problem in homes where there are uninterrupted connections between rooms.
For example if you have a brick wall which has no cavity in it then the vibrations can travel directly through from one side to the other.
Dealing with impact noise involves creating small gaps (decoupling) to disrupt the flow of the vibrations.
Adding rubber insulation (adding mass) to absorb any remaining vibrations is also crucial to soundproofing against impact noise.
Ideally as many methods as possible should be employed in any sound proofing project to achieve the most optimal results.