on the H&S front it is interesting to read all the comments etc posted. items like masks and ear plugs are PPE that you may be required to provide for your employees, however, you should remember that ppe is a last resort and you should have taken all possible steps to eliminate the problem in the first place and show that you have done this. it is important for you to keep records of this in the form of risk assessments which can be very simple. on the subject of ear plugs, if you want to use them it is worth spending the money to get custom fitted ones, you will find that good plugs can eliminate different levels of noise and leave you able to hear people talking.
sorry about the bee in bonnet but being a long serving first aid trainer through st john ambulance i can see the other side of the fence and know it is not worth waiting for something to happen but to plan to prevent it happening