Hearing Safety and Sound Levels
After hearing far too many wild statements like 'the EPA limit is 85 dB' in discussions of this topic, I am extremely grateful to the dance community's resident audio expert, Walter Lenk, for providing the following hard data.
"OSHA Standard 1910.95 on noise in the workplace can be had at:
The applicable employee threshold for a daily 3 hour exposure is 97 dBA SPL (reduced to 95 dBA SPL for daily 4 hour exposure), measured on the A scale of a standard sound level meter at slow response (ANSI standard S1.4-1971).
"[Ed. Note - for full information on the OSHA regulations on hearing conservation, see http://www.osha.gov/SLTC/noisehearingconservation/index.html]
With bad eq, I can easily create a mix that would measure only 85 dB, but that would drive everyone screaming from the hall. In 30 seconds, I could change it to a 90 dB mix that everyone would enjoy. A single number doesn't fully describe a musical event; there is a quality issue to sound, not just a quantity.
Nonetheless, meters have a place, and I use one often. You can get an adequate sound level meter from Radio Shack - the cheaper, analog, model is preferable. From numerous experiments, I've found that if levels are below 86 dB, I get frequent complaints that it's not loud enough. If it hits 94 dB, I get complaints that it's too loud. In between, people smile. Says something to me.
Very loud sound will be exciting for some people, but painful for others. You can't necessarily judge what's too loud for everyone else - you may have compromised part of your hearing previously without even knowing it. Check with several others. If you're male, especially ask women, who (yes, still today) often haven't been overexposed to as many types of environmental noise, and have inherently better hearing in the upper frequencies by way of evolution.
Some people run sound at a lower level for English Country Dance. I wouldn't do this with all bands under all circumstances. But if you have a small event with just a piano and fiddle alone, and quiet dancers, keeping the amplification barely perceptible can make a good event a completely sublime one.
Certainly long before we approach pain, we should be asking ourselves what kind of experience we want to provide. Some bands are known for being rockers in folk clothing, and their experience would be incomplete if it wasn't loud. Others prefer an almost acoustic, or a completely non-amplified event. Personally, I like both. Realize it's not a value judgement, it is a conscious choice to make. Your choice also affects the social character of your event.