...The last is of course safety. HSE regs say that there is an upper noise exposure action value of 85dB daily exposure (still looking for a definition of daily exposure) and peak exposure action is at 137dB. HSE comments that brass section will not benefit from seating reorganisation because their exposure comes from themselves.
Chris
I used to work for OSHA, our safety and health organization here in the United States, retiring after a whole thirty-nine and one-half years of total Federal government service. I had employees who dealt with noise issues on a weekly basis, and I still know my way around our noise regulations pretty well.
The "daily" figure that they (the health and safety folks in the UK) use for computing exposure is an eight hour work day. The sampling used to determine the exposure is usually only six hours or so - they extrapolate the rest.
Here in the United States, the 85 dB on the A scale figure is the "starting point" for hearing protection/conservation. Once a workplace makes the 85 dBA over eight hours level, here they are required to monitor all workplace processes, give annual hearing exams to the employees, and provide hearing protection to those who want it. There is no requirement, however, that it be worn at that level of exposure.
Once the sound pressure levels exceed 90 dBA over an eight hour period, the employer must first attempt to engineer out the noise. If that is not successful, they then must institute administrative controls to bring the exposure time down below 90 dBA. (Permitted exposure times drop as the dBA readings go up.) Only when the other two methods do not or can not work is the use of hearing protection acceptable as an abatement method.
While OSHA, to my knowledge, has never sampled for noise in a symphonic situation, there have been pop situations (and at least one in a topless bar) where the regulations have been applied.
The US Army has gone this one better, performing a comprehensive sampling of a wide variety of noise making operations. (As an example, the main gun on the then-current main battle tank pegs the meter out at 140 dBA.) Included was some sampling data on Army bands. However, the girl who worked on this (and used to work for me) took all of the information with her when she moved up north (and I only kept a copy of what was pertinent to my DVA claim for hearing loss).
The great problem people with "normal" music are the trumpets and the flutes/octave flute. Everything else is "withstandable", but not those two.
The notion that "impact noise" can cause hearing loss is widespread, but really only severe noise levels (like the tank gunnery situation above) will cause loss from impact noise. And, most ears can withstand the levels during a regular two to three hour rehearsal without any permanent damage.
However, the levels that a pipe band generates (remember that the drones are sounding continuously when the pipes are being played) would be of concern due to the high, constant noise level.
Ear plugs, even of the foam, bought-at-the-drug-store type, should be adequate for the sound pressures encountered in a typical music situation (our kind of music). When they get grotty with ear wax, you just throw them in the washing machine with the rest of your laundry, and they clean right up. (Do not run them through the dryer, however - squeeze the excess water out, and let them air dry.)
Rock music folks need the fitted kind, which will offer greater attenuation than will the standard foam plugs. If you play in a standard, highly amplified rock situation, you too should get the fitted ones. They cost a lot more, but they have a level of protection far above the store-bought type.
