Mamun, a resident of Lalmatia, said: "The noise increases during the rush hour when traffic increases on the roads. The impatient drivers using double horns make the condition of the people stuck in traffic jam even worse."

The vehicles are using these horns in the residential areas and even near schools and hospitals making the environment intolerable and annoying.

Ameena Islam, a patient at a privately owned hospital on the busy Outer Circular Road, said: "The loud noise that comes from the street is irritating. But the patients get used to it."

"Loud noise can create deafness, palpitation, cardiac and neurological problems. Such problems are increasing in the city," said Mahbub Khan, a doctor at the hospital.

Bahreen Khan, a senior lawyer of Bangladesh Environmental Lawyers' Association (Bela) said there are specific laws to avoid and reduce noise pollution.

The Bengal Motor Vehicles Rules 1940 says, "No motor vehicle shall be fitted with any multi-tuned horn giving a succession of different notes or with any other sound producing device giving an unduly harsh, shrill, loud or alarming noise."

The Environment Conservation Rules 1997 ensures the standard limit of sound in residential and commercial areas. The standard is 50 decibel in residential areas at daytime and 40 decibel at night. The standard unit in case of mixed area, meaning mainly residential but also used for commercial and industrial purposes, is 60 and 50 decibel.

Bahreen said the actual level of noise pollution is far higher than the limit.

"The awareness programmes conducted by NGOs and the media as well as the formulation of new laws have created some awareness among people but noise pollution has not come down to a satisfactory level," she said.

Most of the people are some way or other reluctant to follow the rules. The banned horns creating harmful loud noise are still on use. "The problem is most of them don't realise that they are breaking the law," said Bahreen.

Different new mechanisms have been introduced to create a loud horn. In private cars the owners install double horns with an option of switching them off.

The owner of such a car on condition of anonymity said: "I know it is illegal. I usually use the louder one in daytime and on the highways. The advantage of using these horns is that heavy trucks and buses give side to my small car when I honk the loud horn."

"But at night I switch the louder one off and turns on the usual one," he added.

Mamun, a mechanic who works at a motor parts shop, said: "The sale of these horns are increasing. Car owners buy these horns because these horns suit any type of cars."

MA Momen, chairman of Bangladesh Road Transport Authority (BRTA), said: "There are laws related to the noise pollution and there will be an amendment in the Motor Vehicle Ordinance 1983 soon. The basic problem that makes the law ineffective is the soft punishment. The amount of fine is too little for the lawbreakers."

Bahreen Khan, however, said that the punishment for polluting atmosphere is as little as Tk 500 in the penal code. But the highest punishment for the same crime is 10 years of rigorous imprisonment and Tk 10 lakh fine in the Environment Conservation Rules 1997 which is more relevant to this issue. She said: "The problem lies in the enforcement of the laws."