Growing noise pollution in the city has greatly affected the hearing of street vendors to policemen to residents living very close to busy junctions. Apart from the rise in the number of vehicles, the unnecessary use of horns is like "adding insult to injury".

Manning the Spencer's junction on a cloudy afternoon, traffic policeman Saravanan (name changed) seems to be a sprightly man with a ready smile. However, beneath the cheerful facade lies the story of his slow descent into partial deafness. The 17 years of service he has put in has made him a victim of continuous exposure to the noise that the vehicles on the city's roads generate.

There are quite a few like him, and they range from street vendors to policemen to residents living very close to busy junctions.

The Government General Hospital recently conducted a study on 670 road users who have been exposed to noise levels of 90 to 100 decibels (for up to eight hours) on a daily basis.

The noise standards, as per the Noise Regulations Rules, 2000, of the Ministry of Environment and Forests, are 65 dB in commercial areas and 55 dB in residential zones.

Nearly 30 per cent of the sample group showed signs of noise-induced hearing loss. A further 25 per cent suffered from sensory neural hearing loss, a condition in which the auditory nerve gets damaged.

There is very little attention to reducing the vehicular noise, says C. Jacinth, Director, Institute of Otorhino Laryngology, Government General Hospital. “Continuous exposure to noise can be extremely harmful. It can lead to giddiness, irritability, rise in blood pressure and even depression in some cases. Noise levels near the Chennai Central station are at times as high as 140 dB,” he says.

According to him, apart from the rise in the number of vehicles, the unnecessary use of horns is like “adding insult to injury”.

The use of multi-tone horns is also a major issue. M. Ravi, Additional Commissioner of Police (Traffic) says that about 10 to 15 cases are booked everyday against those who use air horns. “But unless someone makes a specific complaint or a traffic policeman manning a junction hears the violation, nothing much can be done. It is very difficult to check individually. The police are also not equipped with noise meters,” he adds. A.Ramachandraiah, professor at IIT-Madras, who works in the field of acoustics and noise control, says indiscriminate use of honking as a strategy to navigate the streets is a major factor that demarcates the noise levels of Indian cities from western cities.

A noise map generated at IIT-M last year by measuring levels at 58 sampling points shows that nearly 28 per cent of the city can be categorised as “areas of noise discomfort”. This reduces to 5 per cent at night due to the drop in vehicular flow. Average noise levels in the city have increased by 16 dB since 1985.

Prof. Ramachandraiah says that extensive use of sound barriers on either side of arterial corridors and sound insulation of apartment blocks in high noise zones must be used to mitigate the effects of road traffic noise. Cities such as New York have comprehensive Noise Codes. It also launched ‘Operation Silent Night' five years ago after studies showed that noise pollution significantly altered sleep patterns and increased stress levels.

Sumaira Abdulali, a noise pollution activist and convener of the Mumbai-based Awaaz Foundation, says cities must move towards a regime of transparent reporting of noise levels. ‘Noise mapping UK' is an interactive website where citizens can check a locality's noise level before moving into a new house. Many of the cities also have detailed noise maps. Ms. Abdulali says such data will also be useful for urban planners to take measures to improve the quality of life. “Everyone has a basic right to not hear unpleasant noise. Peace and quite have become the most luxurious things in our cities,” she adds.

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