Rail safety chiefs are to test revolutionary new technology in a bid to stop people being blasted by ultra-loud horns fitted to the latest generation of trains.

The Rail Safety and Standards Board (RSSB) will trial newly developed broadband hooters, which produce a softer, less jarring warning, on trains in Sussex.

The RSSB said it was too early to know how long it would need to test the equipment and warned there was no short term solution.

Manufacturer Brigade Electronics said it would take about two months before the specially designed horns were ready for working trials to begin.

The Brighton-based Noise Abatement Society (NAS), welcomed the initiative but said rail companies could face legal action if they continued to use the booming hooters.

Director Peter Wakeham said: "If the trials are successful and the operating companies will accept these new horns, then problem solved. In the meantime, we still have a serious noise pollution problem."

There have been hundreds of complaints since trains fitted with the new horns, which are more than twice as loud as older hooters, began operating at the end of last year.

Groups such as NAS believe broadband horns, which are quieter than traditional horns but are still easily audible, could end the misery.

Prototype broadband equipment is being tested by police forces, which want to replace loud claxons fitted to patrol cars.

The RSSB said it was eager to find a solution but said new equipment would have to be introduced as part of a national plan.

Head of operations Richard Evans said: "The objective of the trial is to see whether there is a workable alternative to the present technology which can be fitted relatively easily and quickly."

NAS, meanwhile, urged Brighton and Hove City Council to use its powers to force rail operators to stop using the existing horns, particularly at night.

The council said it sympathised with people living by the tracks but the legal situation was very complex.

The new horns are not supposed to be sounded at some level crossings between 11.30pm and 7am but can be used in most other circumstances.

The RSSB expects to publish new guidance early next month.