The BBC have an article

The BBC have an article on complaints from residents about the noise from new louder train horns on SouthCentral Trains rolling stock. This follows an article on BBC South television, and articles in most of the area’s papers, including the Observer here in Chichester.
Firstly, a factual inaccuracy. The train illustrated in the BBC article is a SouthWest Trains class 159, which is neither new nor fitted with the loud type horns. OK, I’ll take my anorak off now.
Secondly, the people who are moaning about the SouthCentral class 375s are probably the same people who moaned about approaching trains not warning users of the Fishbourne Road pedestrian crossing in Chichester, where several people have been hit by trains over the years. The trains now use their horns as they approach that crossing, and as someone who uses the crossing from time to time, I can say for sure that you’re not going to miss the approach of the new trains.
So it seems that people want the railway to be made safer, but only if it is done quietly. Bloody nonsense. If you bought a house by the railway (it has been there for nearly 150 years, after all!), then you must expect noise from the trains, including their horns. Shut up whingeing, and get a life.

Rant over.