Patna: The state pollution control board is reported to have made a move to ask its counterparts in New Delhi and Uttar Pradesh to ban manufacture of multi-tone horns, popular as pressure horns.

Most multi-toned horns used in Bihar are manufactured at small-scale units in Delhi and surrounding areas. "The Pollution Control Board has conducted a few raids and seized horns," said deputy chief minister Sushil Kumar Modi, who also heads the forest and environment portfolio. "But instead of wasting so much energy, it would be better if manufacturing is stopped."

Use of multi-toned horns is banned in Bihar because of the noise pollution it causes. But its use is rampant - especially in commercial vehicles and two-wheelers. Pollution Control Board officials point out that most multi-toned horns were manufactured in Delhi and adjoining areas and they will write to their counterparts there seeking a ban on its manufacturing.

As per the Central Motor Vehicles Act, 1989, no vehicle is allowed to attach multi-tone horns that let out a succession of different notes or any sound-producing device that lets out a harsh, shrill and loud alarming noise.

The Central Pollution Control Board last year asked states to enforce the ban. The World Health Organisation in one of its reports pointed out that prolonged exposure to high-pitched sounds leads to hearing loss.

While most car manufacturers have declared they provide horns with permissible noise in their vehicles, the multi-tone horns are manufactured in small-scale units. There noise level is beyond the 93-112 decibel prescribed under Central Motor Vhicle rules, 1989.