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[klaus]

I am sure that the SPL limits mentioned accommodate peaks in the red zone, but of short enough durations that the average allowable exposure (SPLs over time) remains within legal limits.

[polypals]

That us not how legislation regarding sound levels is upheld.
Go over the set limit according to a calibrated SPL measuring device and you are ready for a fine or much worse closing of the performance.

In general the SPL limits are set quite low like for instance the 93 dBA Kai mentions.
Another thing nobody questions is the measuring method and the way the results are weighed.
Keep in mind the human ear is most sensitive for midrange frequencies.
That also happens to be the range where our hearing is less good protected physically.
Knowing that it would be advisable to change the current dBa measurement to one that emphasizes midrange energy.

There is a lot of incorrect information floating around on this subject.
Too many people talking about things the do not fully comprehend.

[boz6906]

The A-weighing isn't perfect but it's response curve is close to the ear's sensitivity curve, especially at low-to-mid levels.

Many times noise-induced hearing loss occurs at the '4 kHz notch', although there can be other causes (disease, trauma, etc).

We've known this long before line-arrays and Marshall amps:

"The ''4 kHz notch'' has been known to be associated with excessive exposure to noise for more than a century. Toynbee, in his 1860 textbook1, noted a diminution in hearing ''of the 5th fork'' by patients who engaged in the hobby of sport shooting. The ''5th fork'' is the tuning fork with a characteristic frequency of 4096 Hz, or 5 octaves - and thus 5 forks - above middle C (256 Hz). This loss was also termed the ''C5 dip'' until the 1930's when audiometers began to be used, and the ''4 kHz'' nomenclature was adopted."

http://www.audiologyonline.com/articles/five-myths-in-assessing-effects-1292

We really notice a 4 kHz notch more readily because that band is crucial for good speech intelligebility.

And it's not just about peaks, duration is a major factor...

Festival stages can be a real problem, the prod crew can be onstage for 8-10 hours at +100 dB.

"You may be interested to know that the lower levels of exposure are actually riskier than the higher exposures. Because noise induced hearing loss is insidious, and because exposures below 95 dBA may be annoying, but they don't cause pain or discomfort, it is difficult to induce workers to always wear hearing protection when they are working in these levels."

http://emedicine.medscape.com/article/857813-clinical

It's not clear to me why sound engineers' and orchestra members' hearing is not protected by OSHA...

[Jim Williams]

There is a lot of incorrect information floating around on this subject.
Too many people talking about things the do not fully comprehend.

Mostly from 'legislators' that have zero understanding of this subject.
A little education and some common sense will protect you far better than any legislator will.

[AlexVI]

It's not clear to me why sound engineers' and orchestra members' hearing is not protected by OSHA...

In the UK, at least, noise regs are enforced quite strictly within a professional orchestral environment. Many orchestras have nominated employees measuring levels within the band, and all have various means of mitigating against prolonged exposure to high levels (from screens and absorbers placed strategically amongst the musicians to the free provision of high-quality ear plugs).

[soapfoot]

When I was a student at the University of North Texas, they had people from the speech and hearing department (I forget what the degree program was called) come in and measure noise exposure in various chairs of the jazz big bands.

Guitar (where I sat) was somewhere in the middle, being directly in front of the drum set.

By far the most dangerous chair was the 1st trombone-- he sat directly in front of lead trumpet.

[polypals]

Keep in mind musicians are only exposed limited time to high spl.

Engineers and producers are in a different position in CRs.
Their working days lasts 8-10 hours, day after day.

[klaus]

When you expose only one ear to high SPLs over a lifetime, it becomes the analog to a "twin study": What damage can focussed SPLs of a certain volume do to the ear?

A friend owns a professional recording studio. He played violin in orchestras and Irish bands for decades. His hearing in his left ear is shot, and monitor levels need to be adjusted very low, otherwise he hears distortion in the left ear.

[Jim Williams]

I don't think I would want him mixing for me. That's like asking a blind artist to paint a portrait.

Kenny Rodgers said it best:

"You got to know when to hold 'um, know when to fold 'um".

[polypals]

There are two kinds of hearing loss:

Natural loss caused by age.

Loss caused by prolonged periods of exposure to high spl.

The first kind does not have much influence on the ability to work as balance engineer.
The second kind can in extreme cases be a handicap to work professionally.

As long as  I am still able to register virtually all incorrect equalization used by broadcast engineers on voices and hear the difference between proximity effect of cardioids and digital equalization I do not worry about my hearing.

Btw the 4kHz notch seems pretty high to me.
I would say 2 kHz is more likely.

[Kai]

The A-weighing isn't perfect but it's response curve is close to the ear's sensitivity curve, especially at low-to-mid levels.

The A-curve fits quite well to the damage sound can do to your hearing, because it kind of represents the mechanical "gain" that your hearing system achieves with the pinnae, eardrum and hearing bones.

BTW: the 93dBA eff. limits are long term avarage, peaks are allowed up to 135 dB!
All measured at the audience place.
No problem for classical music to stay within these limits.
A bigger problem for classical orchestras can result from workers protectional laws, where the limits are lower.
These would be measured where the musician are, e.g. in front of the brass section.
In fact some classical musicians here in Germany have started to wear earplugs, but must don't.
They don't like it.

Regards
Kai

[polypals]

A friend was bass player in the Royal Concertbuilding Orchestra.
He needed more time for his Bugattis so he faked bad hearing.
He was removed from active duty and received full payment till he died.
Whenever his blown Bugatti missed a beat he was the first to notice it........

[klaus]

(...)In fact some classical musicians here in Germany have started to wear earplugs (...)

I met several players of the Cologne Philharmonic Orchestra last Summer who do. It's not as uncommon as you might think.
Even the concert master (first Violin) of the show I attended did.
They used the Musician's type which is molded to the ear canal. The ones they showed me had the -15dB attenuation plugs.

[soapfoot]

I never leave home without my molded custom earplugs with the 15dB filters. I bought 9 dB filters as well. I keep them in a pouch on my keychain so they are always with me.

I live in New York City. Bus brakes, subways clattering over elevated platforms and then screeching to a stop, taxis with their squeaking worn-out brakes, etc. are more than loud enough to cause damage.

I do wear them when I perform, but their most important function for me is just generalized protection in a very loud city.

[Kai]

I live in New York City. Bus brakes, subways clattering over elevated ...

I have a copy of a study made by Bruel&Kjaer in the 60s that shows that our environmental civilization noises are the main cause for hearing loss that is usually explained as connected to age.
It seems that people living in a calm environment all their life almost do not suffer from hearing loss due to age at all!
Regards
Kai