From NYTimes.com: No Fortissimo? Symphony Told to Keep It Down

Tests showed that the average noise level in the orchestra during the piece, "State of Siege," by the composer Dror Feiler, was 97.4 decibels, just below the level of a pneumatic drill and a violation of new European noise-at-work limits. Playing more softly or wearing noise-muffling headphones were rejected as unworkable.

But across Europe, musicians are being asked to wear decibel-measuring devices and to sit behind see-through antinoise screens. Companies are altering their repertories. And conductors are reconsidering the definition of "fortissimo."

Alan Garner, an oboist and English horn player who is the chairman of the players' committee at the Royal Opera House, said that he and his colleagues had been told that they would have to wear earplugs during entire three-hour rehearsals and performances.

"It's like saying to a racing-car driver that they have to wear a blindfold," he said

It's great that the Europeans care for their workers, but this seems to be a little bit on the extreme.  Music can be loud.  That's part of being a musician.  It's one of the very few occupational hazards of being a musician.