According to The Times, PL refs (PGMOL?) have launched an investigation into whether their whistles could be affecting their hearing, after a study in the US found that a single blast was similar to the noise from a chainsaw. The American study also found that the most commonly used whistles operated in a range most likely to harm hearing.
You have been warned! However what I want to know is whether snoring can have a similar effect on hearing (From experience, Mrs AT and I are certain it does)