Sounds of silence

It is possible to combat noise in existing buildings or new constructions by way of sound-proofing or blocking. Elements such as walls, doors or floors can all be tweaked for acoustic insulation, writes K R Srikanta Prasad.

I  would wonder why the family members of one of my acquaintances speak so loudly over the phone. But when I visited their home, the reason started sinking in slowly. Their home is located in a busy locality of Bangalore and is full of noise. Until recently, this area was an upmarket, residential layout. But it has now become a dense commercial hub and the noise level has shot up. How is one to deal with such specifically urban problems? Is migrating to suburbs the only solution ?

Sound pollution is one of the major problems faced by urban dwellers. The level of noise is measured by decibels. If zero decibel is the threshold of hearing, 20 is a whisper, 40 is noise in a quiet office, 60 is normal conversation and 80 is physically painful. However, in Indian conditions, it is different. In Indian cities, the noisy areas score more than 85 decibels and people still survive. The noise can be due to many reasons. Some possible reasons could be:

Industrial: When the residential locality is close to an industrial suburb, residents are exposed to a high degree of noise. Vehicular movement, factory sirens and high population density contribute to the noise. In case of heavy industry, decibel levels could be much higher.

Traffic: This is a major contributor to noise pollution in urban pockets. Residential pockets near highways are also prone to noise pollution. Non-compliance to traffic rules, indiscriminate use of horns and high-traffic density are major contributors.

Also noise from religious places, loud speakers, political and commercial activities are other reasons. The insensitivity of people towards the environment and the neighbourhood and lack of awareness make it worse. The noise level due to construction activities could be high. Further, unscientific urban design is typical of most Indian cities and is also a cause for noise pollution. The pockets that are earmarked as residential turn into commercial hubs. Those who continue to live in such commercial and semi-commercial areas live in agony.

Ill-effects of noise

Noise causes numerous health problems. It is proven that prolonged exposure to noise can cause mental tension, agitation and headache, high blood pressure, cardiac and stomach related problems, psychological disorders, accidents and partial to complete deafness. Noise also has a negative effect on animals and birds.

What is the way out if you want to continue living in the same locality, despite noise? It is possible to combat noise in existing buildings or new constructions by way of sound proofing or blocking. These methods can lower or eliminate the effects of exterior noise. Various elements in buildings can be addressed to mitigate noise levels. They are listed as below:

Windows: This is the most important element to be taken care of in a residential acoustic insulation. Double pane windows or a second interior window is a good option. Double-glazed window shutters, two glasses with air gap in between is also very effective.

Window curtains will have to be appropriate. Double heavy curtains or air trapped honeycomb material can be used and for the windows, PVC or wooden sections are better than metal sections.

Doors: Double leaf doors or double glazed doors are a good option. The material and the thickness has to be perfect. Acoustic foam can be used between two panels of the door shutter. Using acoustic door seals will dampen the noise to a great extent.

Walls: Walls can be constructed with hollow blocks that have terracotta-like material.

Cavity walls, i.e, two walls built with an air gap in between, are very efficient. Walls can be panelled with wood, boards or PVC laminated acoustic panels. Gypsum board is also commonly used. Even wood paneling with an air gap helps.

Ceiling: Ceilings can also be a major source of exterior noise. False ceiling with appropriate material like a mineral fibre board is required for sound proofing.

Floors: Carpets with sound insulation material, wooden flooring, terracotta, etc, have a better sound absorption quality.

These apart, you can also opt for polymer-based acoustic protection membrane that can be applied to surfaces. Acoustic tiles can be installed in floors, walls and ceilings. Instead of suffering due to high noise levels in urban residential blocks, these methods can be employed to reduce noise. The interiors of the house also need attention; wood work, upholstery, carpets and the furniture design are important. One can opt for the right combination depending on the situation and buy some peace.

(The writer is a consulting civil engineer.)