The road transport and highways ministry is considering a proposal to reduce the maximum permissible decibel range of vehicle horns, a move aimed at curbing noise pollution from compulsive honking on Indian roads.Under the Central Motor Vehicle Rules, 1989, the noise range for horns has been fixed between 93 decibel (dB) and 112dB. The decibel is measured at a distance of 7.5 metres from the horn and at a height of 0.5 to 1.5 metres.“Honking has become a nuisance. In India, it’s more of a behavioural issue. We can bring down the decibel level but drivers will have to stop honking,” a senior road ministry official said.The ministry wants to cap the maximum cut-off range to below 100dB.“We are discussing it with automobile manufacturers. We have had several meetings with the Society of Indian Automobile Manufacturers,” the official said.Experts warned that chronic exposure to sound beyond 93dB for eight hours can cause irreversible hearing loss. Horns are a major contributor to noise pollution in Indian cities.“Besides irritability, ringing in the ears, it can result in hearing loss. You hardly hear any honking abroad, including in Southeast Asia. Why does it happen here? If one follows the rule, keep to his lane there should be no need to honk,” said Dr SC Sharma, head of ENT at the All India Institute of Medical Sciences. In European Union nations, the lower noise limit for vehicle horns is 87dB while the upper limit is 112dB. In Australia and Canada, the upper noise limit is 104dB.Car makers are against the proposed cap of below 100 dB.“The issue has been under discussion for quite some time. We have had meetings with the road transport ministry officials and have agreed to reduce the maximum decibel level of horns to 106db from the current 112dB. We do not want to reduce it further,” said KK Gandhi, executive director (technical), Society of Indian Automobile Manufacturers (SIAM).He argued that horns are required to warn pedestrians. “Reducing the minimum range will make the sound inaudible.”He pushed for curbs on loud multi-tone and pressure horns, especially on buses and trucks.“Despite the Central Motor Vehicle Rules banning multi-tone horns, it is rampantly used by trucks and buses. This is illegal and authorities should take strict penal action.”The decibel level of such horns can go up to 140dB.Several cities in Maharashtra and Tamil Nadu have banned use of multi-tone horns.In July 2016, the National Green Tribunal banned the use of pressure horns in Delhi and the National Capital Region.