Noise is not a very visible form of pollution. Increasingly, we are being assaulted by higher and higher decibel levels, leading to a concomitant rise in stress levels. SONIRA GULHATI checks out an urban menace that is not being taken seriously.

WHEN DID you last experience something called peaceful silence? When you could hear only the insects chirruping or the gentle rustle of leaves? Well, leaves (what's left of them) and insects (what's left of them) are still around, but what has overwhelmed their gentle presence is man-made - noise. Try and watch a movie on TV with sparkling dialogues, and nine times out of ten, you will miss the crucial bits, thanks to the passing roar of a truck in second gear or the irritating whine of an autorickshaw running on adulterated fuel. As for that blender making all that racket in the kitchen, it is in strong competition with that ghettoblaster your kid has put on, though his room is closed.

Silence is golden. It has also become a thing of the past for the urban dweller. As cities grow in size and population, it is becoming increasingly difficult for quiet to prevail. Yes, noise has taken over our lives. Welcome to the big city!

Bangalore, being a large growing city, has over 20 lakh vehicles. Traffic is a major factor in creating unwanted noise. It's not just the noise of the internal combustion engine that is part of the traffic noise, those who control them also add their bit by leaning on the horns every 10 seconds, something unheard of in other countries.

And how many of you have cursed autorickshaws whose silencers have been removed, multiplying the decibel level, forcing you to contemplate homicide? Not only are these vehicles badly designed in every way, their drivers often remove the noise mufflers in the belief that it improves pick-up.

Apart from this kind of noise pollution, there are others like that from loud speakers, generators, construction site equipment, borewell rigs, and so on. All these and more have a deleterious effect on the City dweller's health.

Noise pollution adds to stress levels and in the long run, has been proved to damage our hearing faculties. The louder the noise one is exposed to over a continued period of time, the faster it leads to hearing loss.

Says Dr. G. Mohan, ENT surgeon, Mallya Hospital: "The levels of noise in the City have definitely gone up. The vehicular noise doesn't so much cause damage to hearing but increases stress levels and causes irritability. But prolonged exposure to certain kinds of industrial noise can cause damage to the inner ear and eventually to the nerve cells located there."

Unlike other forms of pollution that assault the eyes and the nose, noise pollution is invisible. With the fast-paced city life, urban dwellers have no time to pause and think about the knocking their other senses are taking, thanks to noise.

Bangaloreans are suffering the effects of noise through increasing volume of traffic. Moreover, the quality of traffic is steadily deteriorating. In a day and age when everything is instant, patience has become obsolete among drivers.

Says Nitya Mohan, a resident of Ulsoor: "There is no longer decorum on the roads. People are just in too much of a hurry and have lost any sensitivity towards fellow citizens."

The problem of unwanted noise affects people living in the central parts of the City as well as those living in what were once quiet areas. Says Krishna Srinivasan, a resident of Dollar Colony, a secluded area: "It used to be quite different when we moved here in the '80s. Now even though we are more than a kilometre away from the main Bellary Road, we can hear the noise of the trucks and other vehicles."

There are laws against noise pollution, and Bangalore has a Pollution Control Board that is very much functional. B. Ramaiah, Senior Environment officer of the Karnataka State Pollution Control Board, blames industries for the increasing level of noise in the City. "The increasing number of offices and industries has added to the noise levels in the City. Offices use captive generators that create a lot of noise," he adds.

The World Health Organisation's guidelines recommend a night-time average level suitable for undisturbed sleep from 35 to 30 decibels (dB), including a peak night-time maximum of 45 dB. In most large cities the average night-time noise levels exceed 45 to 50 dB.

The Indian Environment Protection Act prescribes a certain maximum level of sound that is allowed under the law. "In industrial areas, the maximum allowed limit is 75dB in the day and about 70dB at night. Similarly, in residential areas the (permitted) limit is about 65dB in the day and 60dB at night, and in areas which qualify as silent zones, like areas surrounding hospitals, the prescribed upper limit is about 55dB in the day and 45dB at night," says Mr. Ramaiah.

In cases of bore well drilling at night-time, use of loud speakers or any noise created intentionally by a third party, every citizen is protected under the Environmental Protection Act and has a right to seek help. "Every citizen is protected against noise and has the right to seek help against anybody who is creating noise that is disturbing and illegal. The local police station must immediately be informed and action will be taken," he adds.

According to research, noise intensities above 55 dB are enough to cause annoyance and aggressive behaviour. Also, noise above 75 dB can lead to increased stress levels, increased heart rates and potential hearing loss.

A recent study by two engineering students in the City on noise levels at two major traffic junctions turned up alarming statistics. Most buses, autorickshaws, and motorcycles grossly exceeded the noise level, with one of the buses touching as much as 100 dB. On M.G. Road, the levels were as much at 82.5 dB.

With society becoming noisier than ever, it is up to each one of us to do our bit in taking pre-emptive measures. Otherwise, we will soon turn into a society of noisy yet deaf people! The time to start is now. Is there anyone listening?