http://www.uk-legislation.hmso.gov.uk/si/si2005/20051643.htm
Just a reminder of another bit of legislation that comes into force on the 6th April 2008 to make our lives a bit more difficult.
My understanding is that if noise levels go above 85db then you have to provide some form of protection such as earplugs to any helpers/roadies/employees. Not sure what the position is about using them yourself (unless you are a limited company in which case you will be an employee)
The other alternatives is to use a noise meter and keep the volume below 85db.


which is actually (to simplify it somewhat) a calculation of the average noise exposure over a working day.