What is soundproofing?
Soundproofing, also known as sound blocking, basically refers to the insulating materials used to stop the sound to enter or leave the room. Soundproofing materials are in most of the cases solid and heavy. To be more precise, the action of physically blocking sound requires it to be dense and thick enough to reflect the sound and keep it inside closed space. On the other hand, it is not always the best solution when someone is dealing with the noise factor. However, there are definitely circumstances when soundproofing is the most suitable method. Theaters, cinemas and TV/Radio stations often require soundproofing of their facilities. The reason is to resolve issues of unwanted sound entering or leaving the room.
Two distinct soundproofing problems may need to be considered when designing acoustic treatments. One is to improve the sound within a room (reverberation). Another one is to reduce sound leakage to/from adjacent rooms or outdoors (sound transmission class and sound reduction index). Producers use acoustic quieting and noise control to limit unwanted noise. Soundproofing can suppress unwanted indirect sound waves such as reflections that cause echoes and resonances that cause reverberation. It can reduce the transmission of unwanted direct sound waves from the source to an involuntary listener through the use of distance and intervening objects in the sound path.
There are 3 main aspects that need to be taken into consideration when dealing with soundproofing :
The energy density of sound waves decreases as they spread out so that increasing the distance between the receiver and source results in a progressively lesser intensity of sound at the receiver. In a normal three-dimensional setting, with a point source and point receptor, the intensity of sound waves attenuates according to the inverse square of the distance from the source.
Refers to reduce resonance in the room, by absorption or redirection (reflection or diffusion). Absorption will reduce the overall sound level, whereas redirection makes unwanted sound harmless or even beneficial by reducing coherence. Damping can reduce the acoustic resonance in the air or mechanical resonance in the structure of the room itself or things in the room.
Absorption is the sound ability to spontaneously convert part of the sound energy to a very small amount of heat in the intervening object (the absorbing material), rather than sound being transmitted or reflected. There are several ways in which a material can absorb sound. The choice of sound absorbing material will be determined by the frequency distribution of noise to be absorbed and the acoustic absorption profile required.
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