Noise is an important criterion in designing quality interior spaces. This aspect is given importance to reduce the risk of hearing loss, psychological annoyance or interference with communication. Sound is a pervasive phenomenon. Increased construction activity and the use of high powered equipment in modern lightweight thin construction systems lead to higher noise levels. This can be distracting and irritating. There are many sources of sound in buildings: voices, human activities, and external noises such as traffic, entertainment devices and machinery. They all generate small rapid variations in pressure. These propagate through the air as sound waves. Sound can travel as vibration waves in solids or liquids too. The terms airborne and structure-borne sound are used depending on the medium sound is travelling. The main sources of outdoor noise are traffic (airplane, railway and highway), blaring loud speakers, children playing and machinery on the road. Conversation of occupants, footsteps, banging of door, operation of water closet, radio, T.V. and music system etc. are the main sources. Noise conditions vary and what is tolerable during the day may be annoying at night. Site planning Here are certain recommendations to reduce distraction via noise to the minimum. The most desirable method is to locate the residential building in a quiet area away from noisy sources like industrial area, railway track, aerodromes and roads carrying heavy traffic. To minimise the decibel level the dwellings should be surrounded by maximum amount of plants and grassed area and minimum hard surfacing. Internal planning The orientation of a building in a locality should be planned in such a way as to reduce the noise disturbances from the neighbourhood area. The non-critical areas such as elevators, kitchen, toilet etc can be located on the noisy side, keeping bedroom and living room on the quieter side. Windows and doors should be away from the noisy side. The window should not be closer than 30 m from road traffic. It is preferable to locate the window on a wall at right angles to the noise to avoid it. Boundary wall or plantation should be in-between the traffic and window. A comparison An analogy can be made between a noise source and a light bulb. A light bulb is rated to dissipate a particular number of watts of power. The bulb will always dissipate the same amount of power independent of its surroundings. However, the same bulb may appear to brighten a room covered with shiny reflecting walls more than another with dull black walls. Similarly the bulb might be adequate in a small room, but in a large room might appear very feeble. This is an exact parallel to the acoustical situation. Air borne noise Air borne noise can be suppressed by providing insulation. The insulation will also depend on type of doors and windows. All partitions should be sealed where they butt against the wall. Ventilating ducts should be designed carefully to avoid noise communication. All equipment that generate noise should be selected carefully. Lift motors should be mounted on resilient supports. Electric fans should be insulated and isolated by rubber mounts. If all the above does not reduce your noise problem, have the earplugs handy! ............ Internet
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