Soundproofing a Room

How to soundproof a room in your home

New soundproofing regulations has come into force in England and Wales on July 1st 2003 to address noise pollution and to improve the sound insulation between rooms in hostels, hotels and residential homes, as well as in and between dwellings. It's called " Resistance to the Passage of Sound".

One good thing about this is that basically no alterations or improvements has to be made by the homeowner in future homes, because these regulations were also applicable to new buildings erected after it came into force. Some people are really extremely sensitive to sound, especially when they try to sleep and we'll look at some of the options to curb noise pollution in and around the house.

Characteristics of sound

Sounds are waves or vibrations that travel through a medium. Some of these mediums are more resistant than others, as iron is more resistant than air. Concrete will block more sound waves than a gypsum board, mostly because of the weight. Simply blocking sound from being transmitted through air is not enough. That's why covering a room with egg trays won't be of very much help.

Sound cannot be transmitted between two objects unless they are connected. Air won't make that connection, but a solid object will. If you press your ear against a railway track, you can hear the train coming long before you can see it. Sound-proof studios are often set on rubber isolators and springs and may also be placed within another room, often with a layer of absorptive material in-between.

Sound can bounce back and forth between smooth walls and when there is no absorptive material in-between, the noise it creates can be very annoying. If you can't change anything about the way your house or room is built then secondary solutions will have to do.

Soundproofing solutions

If money is a problem, but a solution is required urgently, then something simple as a carpet or drapes may greatly reduce the noise. Material hung on the wall will make a big difference, especially if it's heavy and for a cheap, intermediate solution, even cardboard egg trays will help a lot. For noise that enters through the gaps around doors, weatherstrips may be used.

For a more effective solution, walls can be treated to make a room soundproof. This will require something to be added to it, like a carpet or special panelling, together with soundproof curtains in front of the windows. Walls and furnishings with rough surfaces will also absorb sound to some degree, because sound is not deflected from rough surfaces. There are acoustic sprays, mostly cellulose, available that can be sprayed against walls or ceilings to help curb the noise.

A very effective material to use is mass loaded vinyl (MLV). It can be used as carpet underlayment for comfort, durability and noise control. This is a replacement for lead coating that was used in the past for the same purpose. It can be glued or stapled to walls and then covered with drywall for excellent noise control. It can also be used on the ceiling.

Acoustic foams are also used and are specifically designed for soundproofing and are usually fitted on walls and in the loft.

The usual insulation material in the loft can also serve as a soundproofing material. Windows are big transmitters of noise from outside and double-paned or vinyl-framed windows will greatly reduce that problem. The glass on the outside of these windows must be as thick as possible and the greater the distance between the windows the better the soundproofing. Acrylic windows are not good at curbing noise, as they have very little mass.

There's even the specialised Soundproofing Window on the market, which is said to reduce noise by 75 to 90 percent. It is an interior window, but can be installed on the outside also. It can open and close and is moderately priced. it actually performs better than the heavy double-paned windows, although the price is the same.

For serious soundproofing of a studio, it's best to make use of a contractor if you can't set up a room within a room, because that is basically the only way to completely soundproof a studio. The doors will also be solid and heavy and the structure holding it should be strong. For more information on soundproofing in the UK, the Building Research Establishment may be contacted at 01923 664500.

A new option that became available is active noise control. A noise-cancellation speaker emits a sound wave with the same amplitude as the original sound, but with inverted phase, or anti-phase. These waves then combine in a process of interference, or phase cancellation, to form a new wave and neutralise each other. It's not very effective when sounds of different amplitudes from different directions are to be cancelled. It works well with something like an engine in a closed environment, such as with a submarine.




